摘要:

AXDREWS ON THE CONTINUITY OF THE GASEOUS XI.-On the Continuity of the Gaseous and Liquid States of Matter. By THOMAS ANDREITS M.D. F.R.S. Vice-president of Queen's College Belfast. (From the Philosophical Transactione for 1869.) IN 1822 M. Cagniard de la Tour observed that certain liquids such as ether alcohol and water when heated in hermetically sealed glass tubea became apparently reduced to vapour in a space from twice to four times the original volume of the liquid. He also made a few numerical determinations of the pressures exerted in these experiments." In the following year Faraday succeeded in liquefying by the aid of pres-sure alone chlorine and several other bodies known before only in the gaseous f0rm.t A few years later T hilorier obtained solid carbonic acid and obsei-ved that the coefficient of expan-sion of the liquid for heat is greater than that of any azriform body.$ A second memoir by Faraday published in 1845 * Annales de Chimie 2&mesGrie xxi pp.127' and 17d; also xxii p. 410. t Philosophical Transactions for 1823 pp 160-189. $ Annales de Chimie 28me ssrie lx pp. 427 432. F’ AND LIQUID bThTES OF MATTER. ID greatly extended our knowledge of the erects of cold and pressure on gases.” Regnault has examined with care the absolute change of volume in a few gases when exposed to a pressure of twenty atmospheres and Pouille t has niade some observations on the same subject. The experiments of N a t t ere r have cai-ried this inquiry to the enormous pressure of 2,790 atmospheres; and although his method is not alto- gether fiee from objection the results he obtained are valuable and deserve more attention than they have hitherto received.7 In 1861 a brief notice appeared of some of my early experi- ments in this direction.Oxygen hydrogen nitrogen carbonic oxide and nitric oxide were submitted to greater pressures than had previously been attairaed,in glass tubes and while under these pressures they were exposed to the cold of the carbonic acid and ether bath. None of the gases exhibited any appearance of liquefaction although reduced to less than of their ordinary volume by the combined action of cold and pressure.$ In the third edition of 11ill e r’s ‘‘Chemical Physics,” published in 1863 a short account derived from a private letter addressed by me to Dr.Miller appeared of some new results I had obtained under certain fixed conditions of pressure and tempe- rature with carbonic acid. As these results constitute the foundation of the present investigation and have neT-er been published in a separate form I may perhaps be permitted to make the followiiig extract from my original commuuication to Dr. Miller. ‘‘ On partially liquefying carbonic acid by pressure alone and gradually raising at the game time the temperature to 88’ Fahr. the surface of demarcation between the liquid and gas became fainter lost its curvature and at last disappeared. The space was then occupied by a homo-geneous fluid which exhibited when the pressure was suddenly diminished or the temperature slightly lowered a peculiar appearance of moving or flickering sti& throughout its entire mass.At temperatures above 88”110 apparent liquefaction of carbonic acid or separation intc two distinct forms of matter could be effected even when a pressure of 300 or 400 ctt1110-4 spheres was applied. Nitmug oxide gave analogom results.”$ * Philosophical Transactions for 1845 p. 155 t Poggendorff’s Annalen xciv p. 436. $ Report of the British hebociation for 1861. Transactions of Sections p 76. § Miller’s Chemical Ph?sics 3rd edition p. 328. GZ ANDREW3 ON THE COKTINWITY OF TI-IE OASEOIfS The apparatus employed in this investigation is represented in the Plate opposite page 94. It is shown in the simple form in which one gas only is exposed to pressure in Figs.1and 2. In Fig. 3 a section of the apparatus is given and in Fig. 4 another section with the arrangement for exposing the compressed gas to low degrees of cold in racuo. In Figs. 5 and G a compound forin of the same apparatus is represented by means of which two gases may be siniultaneously exposed to the same pressure. The gas to be compressed is introduced into a tube (fa)having a capillary bore from a to b a diameter of about 2.5 millimetres from 6 to c and of 1-25niillimetre from c to J’. The gas carefully c-lricd is passed for several hours through the tube open at both ends as represented below. The presence of a column of water of two metres in lieiglit was neccssary to maintain a moderate stream of gas throiigli the fine capillary tube.In tlie case of carbonic acid the ggs after passing through the apparatus was made to bubble by meaiis of a connecting-tube through mercury rind a portion was collected from time to time in order to ascer-tain its purity. The current was contiiiued till the residual air after the action of caustic potash was reduced to a constant minimum. In repeated trials I found that in the complicated arrangements I had to adopt the residual air could not be reduced to less than from to of the entire volume of the carbonic acid. Even after continuing the current for twenty-four hours this residue appeared ;and in discussing some of the results obtained by exposing the gas to high pressures the presence of this small quantity of air must be carefully taken into account.The capillary end at a was then sealed and the other end was also closed and afterwards introduced under a surface of pure mercury contained in a glass capsule. The lower end while under the surface of the mercury was opened and heat applied so as to expel a little of the gas. On cooling contraction occurred and a short column of mercury entered. The cnpsulc mid lower end of the tube were tlrlerl AND LIQUID STATES OF RIATTER. 77 placed under the rcceiver of an air-pump and a partial vacuuin was formed till about one-fourth of tlie gas was removed. 011 restoring the pressure a column of mercury entered and occu- pied the place of tlie expelled gas. By withdrawing the end of the tube from below the surface of the mercury in the capsule and again exhausting cautiously the column of mercury could be reduced to any required length.The tube when thus filled had the form shown (Figure p. 76.). Two file marks liad been made one at d the other at e in the narrow part of tlie tube about 10 millims. distant from each other and the capacity of the tube from a mark ne:x cc to d and also from the same mark to e had been determined by fillingit with mercury at a known temperature and weighing the mercury. The tube was now placed accurately in a hori-zoiital position and connected by an air-tight junction with one limb of a long U-tube filled with mercury. Each limb of the U-tube was 600 millims. long and 11 millims.in diameter. By removiiig mercury from the outer limb of the U-tube a partial vacuum was obtained and the column of mercury (m n) was drawn into the narrow tube (d f). From the difference of capacity of this part of the tube the column of mercury was iiow about four times longer than before. It was easy with a little care so to adjust tlie pressure that the inner end of tilie nier-curial column coincided with the mark e. When this wiis accomplished the difference of level of the niercury in the two limbs of tlie U-tube was accurately read by means of it cathetometer and the height of the barometer as well as the temperature were carefully noted. Similar observxtions were made with the gas expanded to the mark d. Two incleyendeut sets of data were thus obtained for calculating the vol~~nie of the gas at 0" C.and 760 niillims. and the results usually :igr.ec.d to less than TG&c part. The tube after being cliscoimectecl with the U-tube was cut across a little beyond e as shown (Figure p. 76) and was now ready to be introduced into tlie pressure apparatus. The capillary tubes were calibrated with great care and their mean capacity was determined by weighing a colunin of niercury whose length and position in the tube were accurately observed. One millim. of the air-tube used in tliese experiments liad an average capacity of 0.00002477 cub. centim. and 1 millini. of the carbonic acid tube of 040003376 cub. centim. A talde ww ANDREWS ON THE CONTINUITY OF THE GASEOUS constructed showing the corrected capacity of each capillary tube from the sealed end for every millimetre of its length.An allowance of 0.5 millim. was made for the cone formed in sealing the tube. For the sake of clearness I have described these operations as if they were performed in the detached tube. In actual practice the tube was in the brass end-piece before it was filled with gas (Fig. 7). The construction of the apparatus employed in these expe- riments will be readily understood from Figs. 3 and 4 which exhibit a section of the simple form. Two massive brass flanges are firmly attached round the ends of a cold-drawn copper tube of great strength and by means of these flanges two brass end-pieces can be securely bolted to the ends of the copper tube and the connections made air-tighi by the inser- tion of leather washers.The lo-wer end-piece (Fig. 7) carries a steel screw 180 millims. long 4 millims. in diameter and with an interval of 0-5 millim. between each thread. The screw is packed with care and readily holds a pressure of 400 atmo-spheres or more. A sinllilar end-piece attached to the upper flange carries the glass tube containing the gas to be com-pressed (Fig. 7). The apparatus be€ore being Rcrewed up is filled with water and the pressure is obtained by screwing the steel screw into the water." In the compound apparatus (Figs. 5 and 6) the internal arrangements are the same as in the simple form. A. communi-cation is established between the two sides of the apparatus through a b.It is indifferent which of the steel screws below is turned as the pressure is immediately diffilsed through the interior of both copper tubes and applied through the movable columns of mercury to the two gases to be compressed. Two screws are employed for the purpose of giving a greater com- mand of pressure. In Fig. 5 the apparatus is represented with- out any accessories. In Fig. 6 the same apparatus is shown with the arrangements for maintaining the capillary tubes and the body of the apparatus itself at fixed temperatures. A rectangular brass case closed before and behind with plate glass rJurroiinds each capillary tube and allows it to be main- * The first apparatus mas constructed for me by Mr. J. Cumine of Belfast to whose rare mechanical skill and valuable suggestions 1 have been greatly indebted in the wliole coime of this ddhult investigation.AND LIQUID STATES OF MATTER. tained at any required temperature by the flow of a stream of water. In the figure the arrangement for obtaining a current of heated water in the case of the carbonic acid tube is shown. The body of the apparatus itself as is shown in the figure is enclosed in an external vessel of copper which is filled with water at the temperature of the apartment. This latter arrange- ment is essential when accurate observations are made. The temperature of the water surrounding the air-tube was made to coincide as closely as possible with that of the apart- ment while the temperature of the water surrounding the carbonic acid tube varied in different experiments from 13* C.to 48' C. In the experiments to be described in this communica-tion the mercury did not come into view in the capillary part of the air-tube till the pressure amounted to about forty atmo- spheres. The volumes of the air and of the carbonic acid were carefully read by a cathetometer and the results could be relied on with certainty to less than 0.05 millim. The temperature of the water around the carbonic acid tube was ascertained by a thermometer carefully graduated by myself according to an arbi-trary scale. This thermometer was one of a set of four which I constructed some years ago and which all agreed so closely in their indications that the differences were found to be alto- gether insignificant when their readings were reduced to degrees.I have not attempted to deduce the actual pressure from the observed changes in the volume of the air in the air-tube. For this purpose it would be necessary to know with precision the deviations from the law of Mario t t e exhibited by atmospheric air within the range of pressure employed in these experiments and also the change of capacity in the capillary tube &om internal pressure. In a future communication I hope to have an opportunity of considering this problem which must be resolved rather by indirect than by direct experiments. As regards the deviation of air from Mariott e's law it corresponds accord- ing to the experiments of Regnault to an apparent error of a little more than one-fourt,h of an atmosphere at a pressure of twenty atmospheres and according to those of Natterer to an approximate error of one atmosphere when the pressure attains 107 atmospheres.These data are manifestly insuf-ficient and I have therefore not attempted to deduce the true pressure from the observed change of volume in the air-tube. ANDREWS ON THE CONTINUITY OF THE GASEOUS It will be easy to apply hereafter the correctiona for true pres- Sure when they are ascertained and for the purposes of this paper they are not required. The general form of the curves representing the changes of volume in carbonic acid will hardly undergo any sensible change from the irregularities in the air- tube; nor will any of the general conclusions at which I have arrived be affected by them.It must however always be understood that when the pressures are occasionally spoken of as indicated by the apparent contraction of the air in the air-gauge the approximate pressures only are meant. To obtain the capacity in cubic centimetres from the weight in grammes of the mercury which fillud any part of a glass tube the following formula was used :-where C is the capacity in cubic centims. W the weight of the mercury which filled the tube at the temperature t 0*000154the coefficient of apparent expansion of mercury in glass 13.596 the density of mercury at Oo,and 1*00012the density of water at 4'. The volume of the gas V at 0' and 760 millims. of pressure7 was deduced from the double observations as follows :-h-Gl v=c.-1 + 1 .-ut 760 where C is the capacity of the tube (Figure page 76) from a to d or from a to e t the temperature tc the coeEcient of expan-sion of the gas for heat (0-00366 in the case of air 0-0037 in that of carbonic acid) h the height of the barometer reduced to 0" and to the latitude of 45",d the difference of the mercurial columns in the U-tube similarly reduced.Having thus ascertained the volumes of the air and of the carbonic acid before compression at 0' and 760 millims. it was easy to calculate their volumes under the same pressure of 760 millims. at the temperatures at which the measurements were made when the gases were compressed and thence to deduce the values of the fractions representing the diminution of volume.But the fractions thus obtained would not give results directly comparable for air and carbonic acid. Although the capillary glass t'ubea in the apparatus (Fig. 6) communicated with the AND LIQUID STATES OF MATTER. same reservoir the pressure on the contained gases was not quite equal in consequence of the mercurial columns which confined the air and carbonic acid being of different heights. The column always stood higher in the carbonic acid tube than in the air-tube so that the pressure in the latter was a little greater than in the former. The difference in the lengths of the mercurial columns rarely exceeded 200 millims. or about one-fourth of an atmosphere. This correction was always ap- plied as was also a trifling correction of 7 millims.for a differ-ence of capillary depression in the two tubes. In order to show more clearly the methods of reduction I will give the details of one experiment. Volume of air at 0' and 760 millims. calculated from'the ob- servations when the air was expanded to ae 0.3124 cub. c en tim . Volume of same air calculated from the observations when the air was expanded to a d 0.3122 cub. centiin. Mean volume of air at 0' and 760 millims. 0.3123 cub. centim. The volumes of the carbonic acid deducd in like manner &om two independent observations were 0.3096 cub. centim. and 0.3094 cub. centim. Mean 0.3095 cub. centim. The length of the column of air after compression at 10'976 in the capillary air-tube was 272.9 millims.corresponding to 0.006757 cub. centim. Hence we have 0*006757 -1 6' = 0.3123 x 1.0394 -48.04' Bnt as the difference in the heights of the mercurial columns in the air-tube and carbonic acid tube after allowing for the differ- ence of capillary depression was 178 millims. this result re- quires a further correction (% of an atmosphere) in order to render it comparable with the compression in the carbonic acid tube. The final value for 6 the fraction representing the ratio of the volume of the compressed air at the temperature of the experiment to its volume at the same temperature and under the pressure of one atmosphere will be s=-1 47.81' The corresponding length of the carbonic acid at 13'922 in its 82 ANDREWS ON THE CONTINUITY OF THE GASEOUS capillary tube was 124.6 millims.equivalent to 0*004211cub. centim. from which we deduce for the corresponding fraction for the carbonic acid 0*004211 -1 e= -~ 0.3095 x 1.0489 77-09' Hence it follows that the same pressure which reduced a given volume of air at 10°*76to n!si of its volume at the 8ame temperature under one atmosphere reduced carbonic acid at 13O.22 to w!5T of its volume at the temperature of 13O.22 and under a pressure of one atmosphere. .Or assuming the com-pression of the air to be approximately a measure of the pres-sure we may state that under a pressure of about 47.8 atmo-spheres carbonic acid at 13"*22 contracts to +,T of its volume under one atmosphere. In the following Tables 6 is the fraction representing the ratio of the volumes of the air after and before compression to one another e the corresponding fraction for the carbonic acid t and t' the temperatures of the air and carbonic acid respec- tively I the number of volumes which 17,000 volumes of carbonic acid measured at 0" and 760 millims.would occupy at the temperature at which the observation was made under the pressure indicated by the air in the air-tube. The values of I are the ordinates of the curve lines shown in the Figure page 85". * As I is the entire volume to which the carbonic acid is reduced it does not always refer to homogeneous matter but sometimes to a mixture of gas and liquid. Its yalue in the example given in the text is obtained as follows ;-0'004211 I = 1'7000.-= 231.3. 0.3095 When I is homogeneous 1;represents the density of the carbonic acid referred to car- bonic acid gas at the temperature t' and under a pressure of one atmosphere. AND LIQUID STATES OF MATTER. TABLEI.-Carbonic Acid at 13O.1. 6. t. e. t'. 1. 15.75 15-18 234.1 10.86 13.18 221-7 10.86 13.09 220.3 10.86 13.09 168-2 10.86 13.09 125.5 10.86 13-09 92-7 10.86 13.09 66-3 10-86 13.09 52.0 10.86 13.09 46.3 10.86 13.09 38.5 10-86 13.09 37% 10.86 13.09 37.1 10%6 13.09 35.6 I0*86 13.09 34.9 It will be observed that at the pressure of 48989 atmospheres as measured by the contraction of the air in the air-tube lique- faction began. This point could not be fixed by direct obser- vation inasmuch as the smallest visible quantity of liquid represented a column of gas at least 2 or 3 millinis.in length. It was however determined indirectly by observing the volume of the gas OO.2 or 0°*3above the point of liquefaction and cal- culating the contraction the gas would sustain in cooling down to the temperature at which liquefaction began. A slight in-crease of pressure it will be seen was required even in the early stages to carry on the process. Thus the air-gauge after all reductions were made indicated an increase of pressure of about one-fourth of an atmosphere (from 48.89 to 49-15 atmo-spheres) during the condensation of the first and second thirds ANDREWS ON THE CONTINUITY OF THE GASEOUS of the carbonic acid.According to theory no change of volume ought to have occurred. This apparent anomaly is explained by' the presence of the trace of air (about &a part) in the car- bonic acid to which I before referred. It is easy to see that the increase of pressure shown in these experiments is explained by the presence of this small quantity of air. If a given volume of carbonic acid contain & of air that air will he diffused through a space 500 times greater than if the same quantity of air were in a separate state. Compress the mixture till 50 atmospheres of pressure have been applied and the air will now occupy or be diffused through ten times the space it would occupy if alone and under the pressure of one atmosphere; or it will be diffused through the space it would occupy if alone and under the pressure of & of an atmosphere.While the carbonic acid is liquefying pressure must be applied in order to condense this air; and to reduce it to one-half its volume an increase of & of an atmosphere is required. The actual results obtained by experiment approximate to this calculation. From similar considerations it follows that if a mixture of air and carbonic acid be taken for example in equal volumes the pressure after liquefaction has begun must be augmented by several atmospheres in order to liquefy the \&ole of the carbonic acid. Direct experiments have shown this conclusion to be true. The small quantity of air in the carbonic acid disturbed the liquefaction in a marked manner when marly the whole of the carbonic acid was liquefied and when its volume relatively to that of the uncondensed carbonic acid was considerable.It resisted for some time absorption by the liquid but on raising the pressure to 50.4 atmospheres it was entirely absorbed. If the carboiiic acid had been absolutely pure the part of the curve for 13":l (Figure page 85) representing the fall from the gaseous to the liquid state would doubtless have been straight throughout its entire course and parallel to the lines of equal pressure. 6. -1 46'70 1 wO'0.5 1 G0.29 -1 60'55 -1 G1 00 -1 62.21 -1 62'50 AND LIQUID STATES OF MATTER. 85 TABLEII.-Cap'lronic Acid at 21O.5. t. e. t'. 1. 8-63 2?*46 2729 8-70 21-46 160.0 8.70 21.46 105.0 8.70 21.46 76.3 t>+'hj 8-70 21 *46 49.9 8.70 21.46 41.7 8.70 21.46 41-4 The curve representing the results at 21'95 agrees in general form with that for 13'01 as shown in the above figure.At 13'01 under a pressure of about 49 atmospheres the volume of carbonic acid is little inore than three-fifths of that which a perfect gas would occupy under the same conditions. After liquefaction carbonic acid yields to pressure much more than ordinary liquids ; and the compressibility appears to diminish as the pressure increases. The high rate of expansion by heat ANDREWS ON THE CONTISUITP OF THE GASEOUS of liquid carbonic acid first iioticed by Thilorier is fully con- firmed by this investigation.The next series of experiments was made at the temperature of 31@*1,or 0'02 above the point at which by compression alone carbonic acid is capable of assuiniiig visibly the liquid form. Since I first announced this fact in 1863 I have made carefil experiments to fix precisely the temperature of this critical point in the case of carbonic acid. It was found in three trials to be 30'092 C. or 87O-7 F. Although for a few degrees above this temperature a rapid fall takes place from increase of pressure when the gas is reduced to the volume at which it might be expected to liquefy no separation of the carbonic acid into two distinct conditions of matter occurs so far as any in- dication of such a separation is afforded by the action of light By varying the pressure or temperature but always keeping the latter abore 30O.92 the great changes of density which QCCU~ about this point produce the flickering movements I formerly described resembling in an exaggerated form the appearances exhibited during the mixture of liquids of different densities or when columns of heated air ascend through colder strata.It is easy so to adjust the pressure that one-half of the tube shall be filled with nncondensed gas and one-half with the condensed liquid. Below the critical temperature this distinction is easily seen to have taken place from the visible surface of demarcation between the liquid and gas and from the shifting at the same surface of the image of any perpendicular line placed behind the tube.But above 30O.92 no such appearances are been and the most careful exainination fails to discover any heterogeneity in &hecarbonic acid as it exists in the tube. AND LIQUID STATES OF MATTER. 87 TABLEIII.-Cadonic Acid at 31'01. 6. t. E. t'. 1. 1 54.79 - 101.59 1 so.j5 3q.17 235.4 -1 55'96 11.59 -9 1 31.22 22 7.4 1 57'18 - 11-58 86.5s1 31.15 219.0 1 58 4G - 11.55 90.01. 1 31-19 210.6 1 59.77 11.41 i=EG 1 31.18 202.0 1 F1'1Y 11-40 1 98'07 - 31-20 193.3 1 W67 ~ 11.44 1 105'1 31.19 183.9 1 a.27 11-76 1 109'6_- 31.13 173.0 1 66'90 - 11-73 1 116'2 31.19 163.2 1 67'60 - 11-63 1 121'4 - 31-15 152.4 1 69'39 ~ 11-55 1 134'5 ~ 31-03 140.9 1 71'2.i ~ 11.40 1 147'8 - 31.06 128.2 1 73'26 - 11-45 1 169'0 - 31 39 112.2 1 73'83 - 13-00 1 174'4 ~ 31-08 108.7 1 75.40 11.62 1 311.1 31.06 60.9 7FG 1 11.65 51 1 31-06 5 1.3 1 79'92 - 11-16 3xs.o 1 31-10 49.4 1 82'44 - 11.23 395.7 1 31.07 47.9 11.45 ZG1 31-05 46-7 The graphical representation of these experments it13 shown on page 85 exhibits some marked differences from the curves for lower temperatures.The dotted lines in the figure repre- sent a portion of the curves of a perfect gas {assumed to have the same volume at 0' and under one atinosphere as the carbonic acid) for the temperatiires of 13O.1 31O.1 and ANDREWS ON THE CONTINUITY OF THE GASEOUS 48'01. The volume of the carbonic acid at 31O.1 it will be ob-served diminishes with tolerable regularity but much faster than according to the law of Mariott e till a pressure of about 73 atmospheres is attained.The diniinution of volume then goes on very rapidly a reduction to nearly one-half taking place when the pressure is increased from 73 to 75 atmospheres or only by -&of the whole pressure. The $all is not however abrupt as in the case of the formation of the liquid at lower tem- peratures but a steady increase of pressure is required to carry it through. During this fall as has already been stated there is no indication at any stage of the process of two conditions of matter being present in the tube. Beyond 77 atmospheres car- bonic acid at 31'01 yielded much less than before t>opressure its volume having become reduced nearly to that which it ought to occupy as a liquid at the temperature at which the observa- tions were made.TABLEIV.-Carbonic Acid at 32O.5 6. t. e. t'. 1. -1 1ko -1 3%50 221.7 57% b> YO -1 12.15 -1 32.34 135% 71'52 140'3 -1 12.30 -1 32-45 122.0 73'60 156.0 1 74.02 12.30 -1 32.46 119.1 lW9 1 1 12.40 191.7 32.38 99.3 73 1 -1 78'52 12.50 311'8 32-48 61.1 1 79.77 12-35 351'3 -1 32-54 54.2 -1 -1 w90 12-35 387'8 32-75 49.1 AND LIQUID STATES OF MATTER. 89 TABLEV.-Carbonic Acid at 35O.5. 6. t. e. t'. 1. 15-68 1 82.72 33-49 232.5 15.70 1 bti'Y4 - 35.54 216.2 15-66 1 96'41 - 35.52 199-5 15-66 1 106'0 35-51 181.4 15-75 1 118'4 35.47 162.4 15-79 1 135.1 35.48 142-3 15.52 1 161'2 35-55 119.3 15-61 I 228'0 - 35.55 84.4 15.67 1 351.9 - 35-48 54.6 J5.67 1 373.7 35-50 51.5 15.64 1 387'9 - 35.61 49-6 15.61 1 411'0 - 35-55 46.8 15-47 1 430'2 - 35.53 44-7 TABLEVI.-Carbonic Acid at 48O.1.E. t. I E- t'. 1. 18.67 1 86-44 - 47.95 231.5 15-79 1 9L1.39 48.05 201.4 15.87 1 117'8 - 48.12 170.0 15.91 1 1p6.8 48.25 136.5 15.83 1 1985 - 48.13 200-8 16-23 1 298'4 - 48.25 67.2 VOL. XXIII. H 90 ANDREWS ON THE CONTINUITY OF THE GASEOUS The curve for 32O.5 (page SS) resembles closely that for 31'-1. The fall is however less abrupt than at the latter temperature. The range of pressure in the experiments at 35'05 extends from 57 to above 107 atmospheres. The fa11 is here greatly diminished and it has nearly lost its abrupt character.It is most considerable from 76 to 87 atmospheres where an increase of one-seventh ill the pressure produces a reduction of volume to one-half. At 107 atmospheres the volume of the carbonic acid has come almost into conforniity with that which it should occupy if it were derived directly from liquid car- bonic acid according to the law of the expansion of that body for heat. The curve for 48'01 is very interesting. The fall shown in the curves for lower temperatures has almost if not altogether disappeared and the curve itself approximates to that which would represent the change of volume in a perfect gas. At the same time the contraction is much greater than it mould have been if the law of Mario t t e had held good at this temperature. Under a pressure of 109 atmospheres the carboiiic acid is rapidly approaching to the volume it would occupy if derived from the expansion of the liquid; and if the experiment liad iiot been interrupted by the bursting of one of the tubes it woiild doubtless have fallen into position at a pressure of 120 or 130 atmospheres.I have not made any measurements at higher temperatures than 48O.1 ; but it is clear that as the temperature rises the curve would coiitinne to approach to that representing the change of volume of a perfect gas. I have frequently exposed carbonic acid without making precise measurements to much higher pressures than any marked in the Tables and have made it pass without break or interruption from what is regarded by every one as the gaseous state to what is in like manner universally regarded as tlie liquid state.Take for example a given volume of car- bonic acid gas at 50' C. or at a higher temperature and expose it to increasing pressure till 150 atmospheres have been reached. In this process its volume will steadily diminish as the pressure augmeiits and no sudden diiniiiutioii of volume without the application of external pressure will occur at any stage of it. When the full pressure has been applied let the temperature be allowed to fill till the carl)onic ad has i*e;icliedthe ordinary tern- AND LIQUID STATES OF MATTER. perature of the atmosphere. During the whole of this operation no breach of continuity has occurred. It begins with a gas and by a series of gradual changes presenting nowhere any abrupt alteration of volume or sudden evolutioii of heat it ends with a liquid.The closest observation fails to discover anywhere indications of a change of condition in the carbonic acid or evidence at any periodeof the process of part of it being in one physical state and part in another. That the gas has wtizally changed into a liquid would indeed never have been suspected had it not shown itself to be so changed by entering into ebullition on the reinoval of the pressure. For convenience this process Bas been divided into two stages the compression of' the carbonic acid and its subsequent cooling; but these opera- tions might have been performed simultaneously if care were taken so to arrange the application of the pressure and the rate of cooling that the pressure should not be less than 76 atmospheres when the carbonic acid had cooled to 31O.We are now prepared for the consideration of the following important question. What is the condition of carbonic acid when it passes at temperatures above 31° from the gaseous state down to the volume of the liquid without giving evi- dence at any part of the process of liquefaction having occurred? Does it continue in the gaseous state or does it liquefy or have we to deal with a new condition of matter? If the experiment were made at looo or at a higher temperature when all indications of a fall had disappeared the probable answer which would be given to this question is that the gas preserves it gaseous condition during the compression ; and few would hesitate to declare this statement to be true if tlic pressiue as in Natt erer's experiments were applied to snch gases as hydrogen or nitrogen.On the other hand when the experiment is made with carbonic acid at temperatures a little above 31° the great fall which occiirs at one period of the process would lead to the conjecture that liquefaction had actually taken place although optical tests carefully applied failed at any time to discover the presence of a liquid in contact with a gas. But against this view it may be urged with great force that the fact of additional pressure being always required for a further diminution of volume is opposed to the known laws which hold in the change of bodies from the gaseous to the liqnid state.Besides the bigher the temperature at which ANDREWS ON THE CONTINUITY OF THE GASEOUS the gas is compressed the less the fall becomes and at last it disappears. The answer to the foregoing question according to what appears to me to be the true interpretation of the experiments already described is to be found in the close and intimate relations which subsist between the gaseous and liquid states of matter. The ordinary gaseous and ordinary liquid states are in short only widely separated forms of the same con-dition of matter and may be made to pass into one another by a series of gradations so gentle that the passage shall nowhere present any interruption or breach of continuity.From car-bonic acid as a perfect gas to carbonic acid as a perfect liquid the transition we have seen may be accomplished by a con-tinuous process and the gas and liquid are only distant stages of a long series of continuous physical changes. Under certain conditions of temperature and pressure carbonic acid finds itself it is true in what may be described as a state of in-stability and suddenly passes with evolution of heat and without application of additional pressure or change of tem- perature to the volume which by the continuous process can only be reached through a long and circuitous route. In the abrupt change which here occurs a marked difference is exhibited while the process is going on in the optical and other physical properties of the carbonic acid which has col-lapsed into the smaller volume and of the carbonic acid not yet altered.There is no difficulty here therefore in distin- guishing between the liquid and the gas. But in other cases the distinction cannot be made ; and under many of the condi- tions I have described it would be vain to attempt to assign carbonic acid to the liquid rather than the gaseous state. Car-bonic acid at the temperature of 35O.5 and under a pressure of 108 atmosphcres is reduced to & of the volume it occupied under a pressure of one atmosphere; but if any one ask whether it is now in the gaseous or liquid state the question does not I believe admit of a positive reply. Carbonic acid at 35"-5,and under 108 atmospheres of rpressure stands nearly midway between the gas and the liquid; and we have no valid grounds for assigning it to the one form of matter any more than to the other.The same observation would apply with even greater force to the state in which carbonic acid exists at higher tempe- ratures and under greater pressures than those just mentioned. Fig. 1 Fig. 2. Fig. 3 Fig. 4. 4 Pig. 6 Fig. 5 Fig. 7. AND LIQUlD STATES OF MATTER. In the original experiment of Cagniard de la Tour that dis- tinguished physicist inferred that the liquid had disappeared and had changed into a gas. A slight modification of the con- ditions of his experiment would have led him to the opposite conclusion that what had been before a gas was changed into a liquid.These conditions are in short the intermediate states which matter assumes in passing without sudden change of volume or abrupt evolution of heat from the ordinary liquid to the ordinary gaseous state. In the foregoing observations I have avoided all reference to the molecular forces brought into play in these experiments. The resistance of liquids and gases to external pressure tending to produce a diminution of volume proves the existence of an in- ternal force of an expansive or resisting character. On the other hand the sudden diminution of volume without the application of additional pressure externally which occurs when a gas is compressed at any temperature below the critical point to the volume at which liquefaction begins can scarcely be explained without assuming that a molecular force of great attractive power comes here into operation and overcomes the resistance to diminution of volume which commonly requires the applica- tion of external force.When the passage from the gaseous to the liquid state is effected by the continuous process described in the foregoing pages these molecular forces are so modified as to be unable at any stage of the process to overcome alone the resistance of the fluid to change of volume. The properties described in this communication as exhibited by carbonic acid are not peculiar to it but are generally true of all bodies which can be obtained as gases and liquids. Nitrous oxide hydrochloric acid ammonia sulphuric ether and snlphuret of carbon all exhibited at fixed pressures and temperatures critical points and rapid changes of volume with flickering movements when the temperature or pressure was changed in the neighbourhood of those points.The critical points of some of these bodies were above 100"; and in order to make the observations it was necessary to bend the capillary tube before the commencement of the experiment and to heat it in a bath of paraffin or oil of vitriol. The distinction between a gas and vapour has hitherto been founded on principles which are altogether arbitrary. Ether in the state of gas is called a vapour while sulphurous acid in VOL. XXIII. I ANDREWS ON THE CONTINUITY OF TEIE GASEOUS the same state is called a gas; yet they are both vapours the one derived from a liquid boiling at 35O the other from a liquid boiling at -10'.The distinction is thus determined by the trivial condition of the boiling point of the liquid under the pressure of the atmosphere being higher or lower than the ordinary temperature of the atmosphere. Such a distinction may have some advantages for practical reference but it has no scientific value. The critical point of temperature affords a criterion for distinguishing a vapour from a gas if it be con-sidered important to maintain the distinction at all. Many of the properties of vapours depend on the gas and liquid being present in contact with one another ; and this we have seen can only occur at temperatures below the critical point. We may accordingly define a vapour to be a gas at any tempera- ture under its critical point.According to this definition a vapour may by pressure alone be changed into a liquid and may therefore exist in presence of its own liquid; while a gas cannot be liquefied by pressure t,hat is so changed by pressure as to become a visible liquid distinguished by a surface of demar- cation from the gas. If this definition be accepted carbonic acid will be a vapour below 31' a gas above that temperature; ether a vapour below ZOO" a gas above that temperature. We have seen that the gaseous and liquid states are only dis- tant stages of the same condition of matter and are capable of passing into one another by a process of continuous change A problem of far greater difficulty yet remains to be solved the possible continuity of the liquid and solid states of matter.The fine discovery made some years ago by James Thornson of the influence of pressure on the temperature at which liquefac- tion occurs and verified experimentally by Sir W. Thomson points as it appears to me to the direction this inquiry must take; and in the case at least of those bodies which expand in liquefying and whose melting points are raised by pressure the transition may possibly be effected. But this must be a subject for future investigation; and for the present I will not venture to go beyond the conclusion I have already drawn from dlrect experiment that the gaseous and liquid forms of matter may be transformed into one another by a series of continuous and unbroken changes.AND LIQUID STATES OF MATTER. APPENDIX. The following experiments made at temperatures differing from any of t'he foregoing series are added as they may here-after be useful for reference. 6. t. E. t'. 1 1 48.15 1; *42 75.00 13.76 1 -1 16.45 S'01 11.13 92.53 1 1 11-50 __ 31.91 h7.a5 w14 1 1 13.10 -31.65 71.75 143'5 1 13-20 -1 31.71 73.88 170'5 ~ 1 13-20 -1 33-15 73'92 157'9 1 1 -73'77 12.74 Ijg.Q 33.58 1 1 73.as 13.14 -35.00 144'5 1 -1 -3.89 13.2 1 140'0 36-03 -1 13.27 -1 36.05 76'06 153'4 1 _. it4 -1 35 13.38 lil'l 36.1 1 1 1 36.22 so.74 13.40 197.8 -1 13-45 -1 36-20 83'81 251'4 -1 -1 36-08 86'01 13.50 323'6 -1 88'92 1353 3581 36.18 -1 1 92'06 13.55 377.8 36.28 12

ISSN:0368-1769    

DOI:10.1039/JS8702300074

出版商:RSC    

年代:1870

数据来源: RSC

摘要:

96 331.-"Tote on some Reactions of Alcohols. By ERNESTTHEOPHRON CHAPMAN. (Read February 3rd 1870.) Amylic A Zcohol.-This alcohol as commonly obtained is found to rotate a ray of polarized light to a greater or less extent. In fact it consists of two alcohols the one rotating and the other non-rotating. These two alcohols may be separated though only with great labour by re-crystallising their sulph- amylates of baryta. They may also be separated to a great extent and one (the non-rotating) may be obtained quite pure by distilling the mixed alcohol from soda chloride of calcium acetate of potash and many other substances which are soluble in the alcohol. The non-rotating alcohol is always retained and the rotating alcohol distils over. But unfortunately the case is not quite so simple as it appears; for I find that the rotating alcohol may be converted into the non-rotating alcohol by the very treatment employed to separate it from the non-rotating.I first became aware of this by finding that though the rotation of a fraction of a sample of amylic alcohol could be increased by distilling it with soda still on mixing the frac- tion retained by the soda with that which distilled over the rotation was always found to be less than that of the sample before it had been submitted to treatment. I do not think that either acetate of potash or chloride of calcium has the property of lowering the rotating power but they do not separate the two alcohols so fast as soda does. Absolutely non-rotating amylic alcohol may be obtained in any quantity by distilling a solution of caustic soda in amylic alcohol to dryness.On adding water to the dry mass in the retort and distilling we get an almost non-rotating alcohol which by another similar treatment may be made quite non-rotating. I cannot find that this non-rotat- ing alcohol presents any differences from the common mixed rotating and non-rotating alcohol in other physical properties. The compounds of the non-rotating alcohol do not rotate those of the rotating alcohol do. This remark applies to the iodide bromide chloride nitrate and nitrite. The compounds rotate in the opposite direction to the alcohol. The valerianic CHAPMAN ON SOME REACTIONS OF ALCOHOLS. acid as is well known also rotates in the opposite direction from the alcohol from which it is obtained.It would appear that the internal structure of organic com- pounds is not so permanent as we have been in the habit of thinking. We must therefore most carefully avoid the use of powerful reagents whenever we wish to ekamihe a question of internal structure. In our paper on Butylic Alcohol (Jour. Chem. Soc. March 1869) MI-. Miles H. Smith and I state that ‘‘ butylic alcohol cannot be dried by treatment with sodium. It would appear that hydrated oxide of sodium is more or less decomposed by butylic alcohol water and butylate of sodium being the pro- ducts.” This supposition appears to be quite correct as the following experiments on amylic alcohol tend to prove.About 400 grms. of dry amylic alcohol were placed in a weighed flask along with 9 grms. water. About 11$,grms. of sodium was now added a small portion at a time. The con- tents of the flask were now distilled in the oil-bath to dryness the temperature being allowed to rise to 230 C. at which it was maintained for about two hours. On weighing it was found that the residue weighed 58 grms. In the distillation much water came over at first. The residue in the retort was very light and porous. On adding water to the contents of the retort and distilling amylic alcohol came over accom-panied by water. On adding carbonate of potash and separat- ing the amylic alcohol drying and weighing it it was found to weigh 46 grms. As the alcohol gained hydrogen from the water added (+grm.) we find that the residue must have con- sisted for the most part of amylate of soda with only a small portion of caustic soda.Had it consisted of caustic soda retain- ing amylic alcohol we should only have obtained 38 instead of 45 grms. of the alcohol from it. We thus see that the sodium replaces the hydrogen in the arnylic alcohol under the con-ditions of this experiment rather than the hydrogen in the water. I now took 20 grms. of pure freshly-fused caustic soda and dissolved it in about 500 grms. of amylic alcohol. A clear solution was obtained. It was distilled as in the last case with exactly the same result nearly the whole of the soda being converted into the amylate. In this case the amylic alcohol vapour which remained in the retort after the experi- CHAPMAN ON THE ORGANIC MATTER ment was expelled by a stream of hydrogen. The weight of the amylate of soda was about 56+ grms. Theoretically it should have yielded 55 grms. From t,hese 56+ grrm. 46 grms. of amylic alcohol were obtained. In this case also water was observed to distil out with the amylic alcohol. Here then we see that the sodium in the caustic aoda actually changes place with the hydrogen of the amylic alcohol.

ISSN:0368-1769    

DOI:10.1039/JS8702300096

出版商:RSC    

年代:1870

数据来源: RSC

摘要:

CHAPMAN ON THE ORGANIC MATTER XIIL-ATote on the Orqanic Matter contained in Air. By ERNESTTHEOPHRON CHAPMAN. (Read February 3rd 1870.) THEfollowing slight investigation on the organic matters con- tained in air is published in its present very incomplete state because I do not see any chance of being able to do muchmore to it for a long time to come. When Mr. Wanklyn Mr. M. H. Smith and myself first became aware that we could detect and in a measure estimate the most minute traces of nitrogenous organic matter in water by converting a part or the whole of the nitrogen it contained into ammonia and estimating this by the Nessler test it oc-curred to us that we might extend the process to air by washing the air with water and examining the water.The first experiments on this subject were made by Mr. Wanklyn. He took a large bottle and filled it with the air to be examined added some pure water and agitated the bottle. His results were of an indecisive character I should think because the volume of air operated upon was too small and the method of bringing the air and water into contact was not sufficiently complete. So far as I know the matter rested here until I took it in hand. The first and most obvious ex-periment was to draw air through a Liebig’s potash-bulb ap- paratus charged with water. This was not satisfactory though when about 100 litres had been passed through the bulbs the water was found to contain nitrogenous organic matter ; but if the air was sent through a second set of bulbs they also were CONTAINED IN AIR.99 found to coiitain nitrogenous organic matter in quantity almost equal to the first. The quantities of nitrogenous organic matter separated from the air in this way were also very small. I next tried a tube with twenty-five bulbs blown on it so that the air had to bubble through each of the twenty-five ; this was better but still very bad. I then tried cotton-wool as a filter but found it impossible to get cotton-wool which was itself free from nitrogenous impurities. 1 then tried gun-cotton and found that when made with care it did pretty well but a much thicker plug of it is required than of cotton-wool ; it is very liable to contract organic impurities fi-om the air and if I am not mistaken it sometimes contains nitrogenous organic matter of a kind which yields ammonia when heated with potash and permanganate of potash.I next tried washing the air by con- densing steam in it. This method answered better than any of those described above but as will be seen I found a much simpler method afterwards. I next attempted to wash the a.ir by causing spray to pass through it ; this method is about on a par with the last. I then tried a kind of inorganic paper made of asbestos; the asbestos was crushed by pressure be- tween flat surfaces so as not to break its fibre more than could be helped; it was now ignited and then boiled with dilute potash and permnnganate of potash and the hot liquid with the asbestos suspended in it was poured on to a piece of wire-gauze which had been fastened with plaster of Paris into a funnel.It was now washed with distilled water and then air drawn through it whilst it was still wet. This filter answers T-ery well if well made but it is very troublesome to make. Lastly I employed pumice-stone powdered till it became as fine as very fine sand. It was employed just as the asbestos had been but it only requires to be heated to redness. First a little rather coarse pumice is sprinkled 011 the wire gauze then about half an inch of the fine powder the whole is then damped and air drawn through it. This filter possesses all the advantages required; it removes all the suspended matter from the air and is itself easily rendered free horn every suspicion of organic matter.I con-struct it as follows :-A wide-necked funnel about four inches in diameter is fitted into the neck of a Woulfe’s bottle; a smaller funnel has its neck removed and is slipped inside the larger one so that its rim shall be about an inch within the 100 CHAPMAN ON THE ORGANIC MATTER CONTAINED IN AIR. rim of the other fiinnel. On the inner rim rests a disc of wire- gauze on which the powdered pumice is spread; the other neck of the Woulfe‘s bottle is connected with a large aspirator. When it is wished to examine air the apparatus is first thoroughly cleaned and the pumice is ignited and then boiled with water it is then placed on the wire-gauze and the air to be examined is drawn through the apparatus; the pumice should be damped from time to time.When sufficient air say 100 litres has been passed through the apparatus the pumice is transferred to a retort which contains water that has been freed from ammonia and organic matter the water in the Woulfe’s bottle is added and the operation proceeded with exactly as if it were an estimation of nitrogenous organic matter in a sample of water by the (‘ammonia method.” Some little difficulty will be experienced in managing the boiling and it is for this reason that I prefer pumice to sand. I have not had either time or opportunity to make many examinations by this method ; the general results arrived at are that the air of crowded rooms contains suspended nitro- genous organic matter and in addition such air contains volatile organic bases for when pumice is boiled with carbonate of soda before the addition of permanganate the distillate is found to contain ammonia and organic bases; this is easily proved by dividing the distillate into two portions aid pouring the one into a retort containing a boiling solution of potash and per- manganate of potash.If now the same volume of liquid be distilled over which was added to the permanganate solution it will be found that on adding Nessler test to the portion of the distillate from the pumice which has been treated with per- manganate a very much deeper coloration will be given than that given by the portion which has not been so treated. This method of proceeding is 80 simple and moreover so quick that we can get a very good idea of the purity of the air in a couple of hours.I regard the presence of the volatile bases as of more importance than the solid organic matter because this latter may consist of harmless material such as the hurl from woollen cloth &c. Air collected fiom the neighbourhood of an untrapped sink may be shown to contain notable quantities both of volatile organic bases and of non-volatile organic matter. GLADSTONE ON REFRACTION EQUIVALENTS. I have not hitherto made any experiment the results of which possess any interest further than that they establish the fact that perceptible quantities of ammonia may be extracted from the organic matter contained in 100 litres of air. I have found quantities varying from -02 milligramme up to 035 in the air of rooms ; the quantity of ammonia is very vari- able. The quantity of nitrogen existing as volatile organic bases is extremely difficult to determine but appears generally to run pretty nearly parallel to the amount of ammonia. It was my intention to have carried out a very complete in- vestigation by mean8 of the method here sketched on the ventilation of hospitals fever-wards and the like; I have not now the opportunity of doing so and publish this fi-agment in the hope Lhat some one may be induced to carry out the inves- tigation which I purposed.

ISSN:0368-1769    

DOI:10.1039/JS8702300098

出版商:RSC    

年代:1870

数据来源: RSC

摘要:

GLADSTONE ON REFRACTION EQTJIVALENTS. XIV.-Befraction Equivalents. By J. H. GLADSTONE, Ph.D. F.R.S. [A Lecture delivered before the Chemical Society March 3rd 1870.1 THEREwere three distinct lines of research which led up to ths discovery of refraction equivalents. The first was the influence of temperature ou the refraction of light by liquids ; the second the refraction of mixtures or combinations as compared with that of their constituents; and the third the refractive indices of different members of homologous series of organic com-pounds. ABto the first of these it must have been frequently observed that a liquid bent the rays of light differently when it was heated but the late Rev. Baden Powell seems to have been the first to investigate the matter and the Rev.T. Pelharn Dale and myself carrying out his idea and with his instrument found that both the refraction and the dispersion always de- crease as the temperature rises.* On further examination we * Phil. Trans. 1858 p. 887. GLADSTONE ON REFRACTION EQUIVALENTS. observed a close relation between the change of density and the change of the refractive index minus unity which we termed the ‘‘refractive energy,” and which is expressed in the symbolic language of opticians as p -1. The product of this refractive energy with the volume that is (p -1)vol. or which is the same thing the energy divided by the density that is a! we called the ‘‘specific refractive energy,” and we came to the conclusion that in the case of liquids this specific refractive energy is a constant not affected by temperature.Nevertheless me recognized ‘‘ some influence arising wholly or partially from dispersion which we have not been able to take into account but which gives rise to the slight progression of most of the calculated products and perhaps to the non-inversion of the sensitiveness of water at 4”C. remarked on already by Jamin and ourselves.”* This general conclusion was subsequently confirmed by the experiments of Professor Landol t of Bonn and a rigorous investigation of the matter by Wullnert has shown that we were justified in our belief that pzl, though the best simple d formula does not express the whole truth. The same is ex-hibited by the very careful determinations of the refraction of water at temperatures ranging from lished by Kuh1mann.S 0’ to 100’ C.lately pub- The value of‘this investigation in its bearing on refraction equivalents was that it drew attention to the specific refractive energy pZ1. Heretofore N e w t o n’s ‘‘Absolute refkactive d power,” pL, -1 had generally engrossed the thoughts of d physicists. As to the second line of research that of the refraction of mixtures solutions and eimple combinations Dulon g attempted to show in regard to gases and H 6 ck in regard to some liquids that the absolute refractive power of a mixture is the mean of the absolute refractive powers of its constituents. Mr. Dale and myself however on examining the mixtures of substances 80 widely apart in their refractive power as bisulphide of carbon * Phil.Trans. 1863 p. 323. + Pogg Bnn. cxxxiii 1. X Pogg. Ann. cxxxii 1,177. GLADSTONE ON REFRACTION EQUIVALENTS. 108 and ether or aniline and alcohol came to the conclusion that here also the nearest approximation to the truth was given by adopting p.L-1 1 instead of pz. This explains Dulong's d d observations on gases equally well. This conclusion also has since been fully confirmed by the careful experiments of Wiilln e r. TOpass from a mixture of two liquids to a solution of a gas or a solid is an easy step and at the meeting of the British Association in 1863 we showed among other things that the same law applied when ammonia gas was dissolved in water or when solutions were made of sugar or common salt." The fact that the specific refractive energy of a solid body is not changed by its undergoing solution was rendered probable in the first place by the fact that water phosphorus and sulphur have the same energies in the liquid and solid states;t and it has since been confirmed in other instances and by the dis- covery that salts have the same influence on light whether they be dissolved in water or in alcohol.At an early stage of our enquiry the question naturally pre- sented itself- does an elementary substance retain its specific power of retarding rap when it is combined chemically with other elements? All our early experiments were made with liquids and an affirmative reply was suggested by many con-siderations.One of the most striking I remember was one that is not pointed out in our paper namely that bromoform and bi- bromide of bromethylene which contain respectively 95 and 90 per cent. of bromine have almost the same specific refractive energy and this a remarkably low one almost identical with that of the liquid halogen itself though they differ from it so widely in colour odour and other physical properties. Bromoform ............... CHBr .... 9210 Bibromide of bromethylene .. C,H,Br .... 0222 Bromine .................. Br .... =212 On the other hand however we remarked that isomeric liquids are not always identical in refractive energy and that * Brit. Ausoc. Report 1863. Trans. See. p. 13. -f Ibid. The details of many of these experiments are given in the Quarterly Journal Chem.SOC.,1865,pp. 110-113. GLADSTONE ON REFRACTION EQULVALENTS. the substitution of oxygen for hydrogen in organic compounds effects a much greater amount of optical change in some instances than in others. Hence we ventured to clraw the coil- clusion that ‘‘every liquid has a specific refractive energy com- posed of the specific refi-active energies of its component ele- ments,” but we cautiously added ‘‘modified by the manner of combination.” We subsequently recognized that the combination of hydro-chloric acid gas or sulphuric acid with water is sufficient slightly to modify the refractive energy; we knew that Dutlong’s numbers for the simple and compound gases show that the law of the mean does not hold perfectly true in that region and trying it on several substances we found that the observed numbers differed but not very widely from the cal- culated mean.One of these substances was ether which con- sists of 64.9 per cent. of carbon 13.5 per cent. of hydrogen and 21.6 per cent. of oxygen and taking the specific refractive energy of carbon (Diamond) at -44 that of hydrogen at 1.533 and oxygen at -19 (gases detefmined by Dulong) we obtained-64.9 (*44) + 13.5 (1.533) + 21.6 (019) = .53 Ether = 100 Specific refractive energy deduced from ob-servation ..... . ..... . . ..*. .. . ........ . = 949 The third line of research was the refraction of different homo-logous compounds. Professor D elffs (of Heidelberg) first at-tacked this question in 1853;* Mr.Dale and I made a great many observations,f and Professor L andolt travelled over a similar region at about the same time.$ From these experi- ments it was evident that in ‘‘ all the series containing the com- pound radicals methyl and its congeners,” the specific refrac- tive energies ‘‘increase as the series advances,” and that “the amount of optical change is less between the higher than be- tween the lower members of the series.” L an do1 t subsequently gave the full explanation of this.$ Adopting our p- -1 he multiplied it by the atomic weight P ; d * Pogg. 81,p. 4’10. t Phil. Trans 1863 pp. 325-331. $ Pogg. 117,p. 353 ;122 p. 545. 9 Pogg. 123 p. 595. GLADSTONE ON REFRACTION EQUIVALENTS.and this P he designated the 6' refraction equivalent." d Instead of saying with us that the specific refractive energy of a compound is the mean of the specific refractive energies of its constituents he expressed the same fact thus :-Its refraction equivalent is the sum of the refraction equivalents of its con-stituent elements. The great advantage of this was that it rendered the calculation more simple and permitted of the easy comparison of the optical properties of different substances. By making these comparisons Landolt arrived at the conclu- sion that the refraction equivalent of carbon is 5.0 that' of hydrogen 1.3 and that of oxygen 3.0. Diamond would give 4-85,and Dulong's determination of the gases respectively 1-53 and 3.04.The way of calculating the refraction equivalent of a compound fiwm these data may also be illustrated by ether one of the substances which he likewise examined- C,H,,O = 4(5*0) + lO(1.3) + 3.0 ........ = 36.0 Refraction equivalent deduced from observa- tion.. ................ ................ = 36.26 Lan dolt showed that the calculated and the experimental refraction equivalents were almost identical for a large number of liquids containing C H and 0; and he proposed this as a method of quantitative analysis applicable to many mixtures which could not otherwise be easily determined such as me- thylic mixed with ethylic alcohol. From our old observations additional proof was at once de- rived that carbon might be taken at 5.0 and hydrogen at 1.3 and this being settled it was easy to calculate values for chlorine bromine iodine tin and mercury.These I communicated to the Chemical Society in a verbal discourse together with the values of phosphorus sulphur nitrogen and sodium as deduced from various experiments but these numbers I regarded as only approximately true." There subsequently appeared a valuable paper by Dr. A. Haagen,? in which he examined a variety of liquid halo'id combinations and deduced from them the refraction equivalents of most of the elements I had determined together with those of arsenic antimony and silicium. Chem. News May 26 1865. I-Pogg. 123 p. 125. 106 GLADSTONE ON REFRACTION EQUIVALENTS. His numbers are :-Chlorine,. .... 9.79 Arsenic...... 20.22 Bromine .... 15-34 Antimony.. .. 25.66 Iodine ...... 24.87 Tin.. ........ 19-89 Phosphorus .. 14.93 Silicium. ..... 7*90 Sulphur ...... 16-03 Sodium ...... 4.89 K et t e 1 er" having taken the refraction of liquid sulphurous acid found that it was not in accordance with the known refrac- tion of the gas as loug as he compared their refracbive powers pz, -1 but the two came into agreement when he turned to d the specific refiactive energy PL. The numbers are gaseous d 14.9 liquid 14.6. Schrauf t has written much upon the subject and still con- -1 tends for p?. d The following table of compounds of carbon not mentioned in Landolt's or Haagen's papers will show how closely the experimental agree with the calculated numbers notwithstand- ing the great diversity of the compounds examined.The equivalents adopted are those which I now prefer and repre- sent the line A of the solar spectrum :-C = 5.0 H = 1.3 0 = 2.9 c1 = 9.9 Br = 15.3 I = 24.5 S = 16.0 N = 4.1 K = 8.1 The data which have not hitherto been published are given in the appendix. * Pogg. 154 p 390. f-Pogg. 133,p. 479. 107 GLADSTONE ON REFRACTION EQUIVALENTS. ..... Refraction equivalent . Substance. l?ormula. Condition. Ibserved. 2alculated. .- Olefiant gas .. Amylene..... Hydride of cenanthylHydride of capryl .. Oil of turpentine .. Oil of patchouli .. Colophene .... Hyvdrate of turpentineCamphor .... Peppermint camphor Bihydrate of cajeputWormwood .... Methylated acetone Biityrone ....Laurmtearate of ethylPropionat. e of ethyl Oxalate of ethyl .. Oxalnte of amyl .. Carbonate of ethyl.. Caprjlic alcohol .. Sugar .... Sugar .... Citric acid .... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. Gas...... Liquid .... Liquid .... Liquid .... Liquid .... Liquid .... Liquid .... Solution in alcohol Solution in alcohol Melted .... Liquid .... Liquid .... Liquid .... Liquid .... Liquid .... Liquid .... Liquid .... Liquid .... Liquid .... Crystallised .. Solution in water .. Solution in water .. Liquid .... 15.1 37..6 55 '0 63 .0 72.5 110-0 147'2 89.2 73.1 79*o 75*2 74 -5 33 '9 56 '3 111*5 44 '2 51 '2 99'0 45'9 66 '2 119*3 119.2 60'9 15 *2 38*O 55 *8 63.4 70 -8 106.2 141-6 88.6 73 9 '18 -9 76 3 73.7 33 *3 56 *l 112 *2 43 -8 54 -6 100 *z 46 *7 66 *3 120.5 120-5 61 '4 Racemic acid .... Solution in water .. 45 '5 45 .8 Tartaric acid .. .. Solution in water .. 45 -3 45 '8 Oxalic acid .... .. Solut.ion in water .. 23 *4 24-2 Eormate of potassiumAcetate of potassiumLactate of potassiumSuccinate of potassium Cyanogen .... Cyanide of ethyl .. Cyanide of wtassium .. .. .. .. .. .. .. Shphocyadde of potassiunUrea ...... Solution in water .. Solution in water .. Solution in water.. Solution in water .. Gas...... Liquid .... Solution in water .. Solution in water.. Solution in water .. 20 '2 27.8 76 '3 52-4 9 '2 25 *.6 17'2 33 '5 22 *8 20 .0 27 -8 76 -6 63 *O 9.1 25 .6 17'2 33 *2 21 '3 Nicotine ...... Chloropicrin .... Chloral ...... Bichloride of chlorethyleneHydrochlorate of camphencBromoform...... Bibromide of chlorethyleneBibromide of bromethylenc Iodide of propyl ....Iodoform ...... Chloride of acetyl .... Liquid .... Liquid .... Liquid .... I.iquid .... Liquid .... Solution in alcohol Liquid .... Liquid .... Liquid .... Liquid .... Solution in ether . 74 .3 27 '0 45 '2 47 .5 43 5 82 -1 53 -3 53 -7 59.3 49 *o 77-5 76'4 26 -7 44 '6 43 ,9 43 '6 82'0 52.2 54 '4 50 -8 48 '6 79 *8 Carbonic oxide .... Gas...... 7-5 '7-9 Carbonic acid .... Gas...... 10 .0 10'8 Carbonate of potassium . Solution in water. 28 *8 29 .9 Yet there are exceptions to this agreement with t.heory. The most remarkable is the whole group of the aromatic hydro- 108 GLADSTONE ON REFRACTION EQUIVALENTS. carbons and their derivatives which give refraction equivalents fi-om 6 to 9 above the calculated numbers.I shall discuss these in a separate communication and show reasons for thinking that the anomaly must be due to something in the constitution of the nucleus common to the whole group and which cannot be greater than C6H,. The fact that a substance retains the same specific refractive energy and consequently the same refraction equivalent when dissolved afforded the means of determining the equivalents of a great number of solid bodies which could not otherwise be taken. The idea occurred to me of examining metallic salts in this way in the hope of arriving at the refraction equivalents of the metals. A series of chlorides bromides and iodides were first tried the refractive indices of their solution in water being taken and the due deduction being made for the solvent.The following are specimens of the early results :-Chloride. Bromide. Iodide. Potassium .. .. .. .. 18 *83 25 -09 35 5'2 Sodium Lithium Ammonium .. .. .. . .. .. ,. . . .. .. .. .. 15 *4Q 14 *86 22 *33 21.89 20 -56 28 *53 32 -62 31 *49 38*90 That a chloride had in each case a refraction equivalent about 6 less than the corresponding bromide and about 17 less than the corresponding iodide and that a potassium salt had in each case a refkaction equivalent about 3.2 greater than the corresponding sodium salt about 4 greater than the lithium and about 3.5 less than the ammonium salt seemed enough to prove three things :-lst that the different salts were really comparable with one another in this respect; 2nd that each halogen and each metal retained its own refractive power wit11 whatever it was combined; 3rd that if we were certain of the value of any one of these elements we could determine all the rest.These experiments have been extended to about 180different salts contailzing 28 inorganic salt-radicals and 33 metals. Most of these have been tabulated in a paper sent to the Royal Society last July and now being printed. A variety of methods were employed for determining the CILADSTONE ON REFRACTION EQUIVALENTS. value of potassium. .and they led to the conclusion that the refraction equivalent of that element in its salts is 8.1 subject to an error probably not exceeding 0.1. Starting from this value it was easy to calculate equivalents for every other corn-ponent of these salts in solution .By attacking the question from different points. the following refiaction equivalents have been determiiied for elementarv substaiices :-Element. Atomic weight. Refraction equivalent . Aluminium .. .. .. .. 27-4 8-4 AntimonyArsenic Barium .. .. .. .. .. .. .. .. .. .. .. .. 122 75 137 24*5 15 -4 (other values 2)15.8 Bismuth .. .. .. .. 210 39*2 Boron Bromine Cadmium .. .. .. .. .. .. .. .. .. .. .. .. 11 80 112 4'0 15 '3 In dissolved dta 16*9 13*6 Cesium Calcium Carbon .. .. .. .. .. .. .. .. .. .. .. .. 133 40 12 13*7'? 10-4 5.0 Cerium Chlorine .. .. .. .. .. .. .. .. 92 3595 13*6? 9 '9 In dissolved salts 10 -7 Chromium .. .. .. .. 52.2 15*9 In chromatea 231 Cobalt .. .. .... 58-8 10-8 Copper .. Didymium .. Fluorine .. Glucinum .. .. .. .. .. .. .. .. .. .. .. .. .. 63 -4 96 19 9.4 11*6 16.?0 1-4? 5-7 Gold.... .. .. .. 197 24'0 Hydrogen .. Iodine .. Iron .... Lead.... Lithium .. Magnesium . . Manganese .. Mercury .. Nickel . . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. *. .. .. .. .. 1 127 56 207 7 24 55 200 58*8 1 *3 24.5 12 .0 24.8 3'8 '7-0 12-2 In permanganate 26 '2 ? 21 '3 In compound iodides 29-0 10*4 In hydracids 3 *5 In dissolved salts 27 -2 In ferric salts 20-1 Nitrogen .. Oxygen .. Palladium .. Phosphorus..Platinum .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 14 16 106 -5 31 197-4 4-1.In high oxides 5.3 2-9 22-2 18'3 (other values 1)26.0 Potasaium .. Rhodium . . Rubidium .. Silicon .. Silver .. Sodium .. Strontium .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 39 -1 104 -4 85 -4 28 108 23 87 '5 8-1 24 '2 ? 14'0 '7 *5? In eilicates 6 *8 13-5 (other values !) 49 I 13.6 * See Proc. Royal Society. 1888. p.439. as well 88 complete paper. VOL. XXIII. K 110 GLADSTONE ON REFRACTION EQUIVALENTS. Element. Atomic Refraction equivalent. weight. ~~~ ~ Sulphur , ,. ,. . 32 16 *O (other values 2) Thallium ........ 204 21.6 ? Tin .......... 118 2’7-0 In tetrachloride 19 *2 Titanium ........ 50 25 *5? 10 -8 25 -3? 10.2 22 *3? The sign ?in the above table indicates that the equivalent has been deduced from only one compound or that the different determinations are not fairly accordant. Of the rest some few are I believe as accurate a8 the atomic weights themselves ; but most are open to rectification in the first place of decimals.It will be seen that many of these elements have a double value. This is a source of difficulty but the disadvantage is far more than counterbalanced by the promise it holds out of throwing new light on the constitution of bodies. If an ele ment had always the same refraction equivalent in whatever way it might be combined the determination of the numbers mould be very easy and there might be some curious relations between them but beyond that they could have little interest for the chemical philosopher. If on the contrary every difference in the manner of combination were to affect the rate at which light is propagated by an element the problem would be very complex and valuable deductions would be almost hopeless.The fict however is intermediate between these ;an element usually exerts the same influence on transmitted rays in all analogous compounds and in many that are not analogous but there are differences of composition which do affect this quality and in some cases at least these are coincident with a change of atomicity. Thus iron in all the ferrous salts examined has the equivalent 12.0 but in the ferric salts 20.1. Again in most of the vegetable acids as in other organic compounds hydrogen has a refkction equivalent of 1.3 but on examining hydrochloric hydrobromic aild hydriodic acids I was forced to the conclusion that it was exerting a far greater influence on light an influence that had to be expressed by the number 3.5.This points to some radical difference in the con-atitution of these two classes of acids. GLADSTONE ON REFRACTION EQUIVALENTS. 111 The so-called hydrochlorate of cainphene (artificial camphor) gives a value composed of the ordinary values of carbon hydrogen and chlorine; and this lends great weight to the idea that it is not a compound of the essential oil with hydro- chloric acid C,,H,GHCl but rather a new ternary compound C,,H,,Cl; and with this its known reactions agree. On the other ha.nd thymole C,,H,,O by giving a refraction equivalent much higher than the theoretical is removed from the group of such substances as camphor and placed along with its isomer carvole and additional weight is given to that view which regards it as a homologue of phenylic acid C,H,O.In the table of' carbon compounds given above nitrogen was taken at 4.1 but ammonium in its salts is alwayB about 11.6. Bearing this in mind we may understand the following series which otherwise would appear more irregular indeed far beyond the limits of experimental error. Refraction equivalent. Compound. Formula. Condition. Observed. Calculated. - ~ ~~ Bisulphide of carbon.. . . . . . . . . Sulphocarbonate of ammonium Sulphocarbamate do. Xanthate of potassium . . . . . . . CS2 LiquidCS3(NH& Aqueous sol. CS,NH2NH do. KOCS2C2HS do. 36.7 77.6 59.3 66-2 37.0 76 -2 57.6 64-5 The greatest anomalies have been presented by oxygen.In organic compounds it was estimated by Landolt at 3.0 by myself at 2.9 ; but there are several oxidized hydrocarbons such as thymole or anethole which shew an enormous increase in refraction and dispersion. The estimates of oxygen from the following pairs of compounds are on the contrary less than 2.9 but they are not accordant with one another. KNO = 22.1 CO = 10.03 KNO = 19.3 co = 7.53 -_c__ 0 = 2.8 0 = 2.5 KC10 = 25.0 KRrO = 31.4 KC1 = 18.8 KBr -= 25.1 K % GLADSTONE ON REFRACTION EQUIVALENTS. 0,= 6.2 0 = 6.3 0 = 2.07 0 = 2.1 The following series however give another aspect to the calculation. Substance. I Formula. I Refraction equivalent. I I Sulphide of Yotassium ........................ Sulphite of Potassium ........................Hyposulphite of Potassium .................... Sulphate of Potassium ........................ K2S K2S03 K2S203 K2S04 34.6 35.1 47 .9 33 -1 Here the equivalent of oxygen would seem to be rather a minus than a plus quantity I And this does not stand alone for rnetaphosphoric acid has a smaller value than the phosphorus it containa Phosphorus ............ P = 18.3 Metaphosphoric acid.. .... PHO = 18.0 Orthophosphoric acid .... PH,O = 23.6 Sirnilar indications are given by arsenic stannic and some other acids. This points to the general conclusion not so much that oxygen has several refraction equivalents as that it has the power of greatly modifying the action on light of those elements with which it is combined in a high proportion.On comparing the refraction equivalents in the table given above it will strike most chemists that some of those well- known pairs of elements having the same or nearly the same atomic weight have also the same influence on light as for instance iron and manganese. But these relations are more numerous when we consider the specific refractive energy of the elements instead of their refraction equivalents. Nor is this to be wondered at for it is the energy that is the more characteristic physical property seeing it expresses a simple fact and is independent of theoretical views as to atomic weight. The following pairs may be noted :-Iron ........ 0.214 Aluminium . . 0-307 Manganese . . 0.222 Chromium .. 0.305 GLADSTONE ON REFRACTION EQUIVALENTS.113 Nickel ...... 0.1’77 Antimony .. 0.201 Cobalt ..... 0.184 Arsenic .... 0.205 Bromine .. 0.191 or in salts 0-211 Iodine .... 0.193 do. 0.214 But the most interesting and suggestive comparison is that between the specific refractive energy and the combining pro-portions of those metals that form salts not decomposable by water. By combining proportions I do not mean the ‘‘atomic weights” or what are usually given as “chemical equiva- lents.” but the actual amount which will combine with a certain quantity of a salt radical. say 35.5 of chlorine. In the following table the metals are arranged according to the order of their energies. beginning with the highest . Element. Specific refractive Combining energy.proportion. Hydrogen .............................. 1300 1 Glucinium.............................. 606 4.7 Lithium................................ 540 7 Aluminium ............................ 307 9.1 Chromium.............................. 305 17-4 Magnesium ............................ 293 12 Calcium ................................ 260 20 Zirconium ............................ 249 22.4 Rhodium .............................. 232 34‘8 Manganese .............................. 222 27.5 Iron .................................. 214 28 Sodium ................................ 209 23 Palladium .............................. 208 26.6 Potassium .............................. 207 39-1 Cobalt ................................ 184 29-4 Copper ................................183 31-7 Nickel ................................ 177 294 Didymium ............................ 166 48 Rubidium .............................. 164 42.7 Zinc .................................. 156 32*6 Strontium .............................. 155 43-8 Cerium ................................ 148 46 Platinum .............................. 132 49*3 Silver.................................. 125 108 Gold .................................. 122 65.7 Cadmium .............................. 1el 56 Lead .................................. 120 103 5 Barium ................................ 115 685 Mercury .............................. 107 100 Thallium .............................. 106 204 Cesium ..............................103 133. Uranium .............................. 90 120 GLADSTONE ON REFRACTION EQUIVALENTS. It Will be seen that while the numbers in the first column decrease those in the second pretty steadily increase. Many of the energies will probably be modified on further investiga- tion but there are exceptions which are certainly riot due to errors of experiment ; chromium and potassium may be noticed and the group silver lead and thallium three elements having a certain chemical relationship the combining proportions of which would have to be halved in order to bring them to about their right places in the list. Still the general significance of the table is not to be mistaken. At first sight it might seem that the metal which was more powerful for doing one thing was less powerful for doing another but it should be remenbered that a small combining proportion means a high saturating power.This relation be- tween the two lists of numbers though it has not the exactness which might be desired when we are tracing a physical law points clearly to some connexion between the power of a metallic element to refract the rays of light and its power to saturate the affinities of other bodies. It may be remarked that these metallic elements do not differ from one another so widely in their optical as in their chemical quality the first ranging only from 13 to 0.9 while the second varies between 1and 204. In future I hope to extend this investigation to all the ele- ments to settle those refraction equivalents which are still doubtful and to examine the apparent exceptions especially with a view to determine how far a change of atomicity is accompanied by a change of refractive energy; and beyond all this the question of dispersion offers an inviting but as yet almost untrodden field of enquiry.APPENDIX. Refractive indices. Specific Temp. Substance. Equivalents of solvent. gravity. centigrade. ~~ A. D. H. Hydrate of oil of turpentine.. .... 63.58 alcohol. ........... 0 -819 9" 1'3690 1*3732 1'3846 Camphor.. .................... 4.54 do. ............ 0.866 8 -5" 1-4022 1-4067 1*4205 Bihydrate of cajeput ............ ......................... 0 '916 20" 1.4532 1.4583 1-4745 Oil of wormwood ....................................... 0 -927 20" 1.4543 1*4598 1-4786 Sugar ........................ 9 *lowater ............ 1.340 3" 1-4588 1*4637 1.4771 Succinate of potassium .......... 71 -50 water + 0 *28CIHBO 1-093 9" 1.3517 1-3563 1-3679 water ............ 1,088 25 *5" 1 3762 I *3815 1-3952 Urea,. ........................ 7 ~00 Chloride of acetyl .............. ......................... 1-159 .... 1.3992 1*4042 1*4213 Chloropicrin .................. ......................... 1*678 9" 1*4616 1.4679 1 *4876 Rydrochlorate of camphene ...... 37 *92alcohol.. .......... 0 *823 9" 1*3713 1-375'7 1*3876 Iodoform.. .................... 38-54 ether.. ............ 0 '820 9" 1*36'71 1.3716 ...... Sulphocarbonate of ammonium .. 35.47 water ............1.065 .... 1*3918 1'3988 ...... Sulphocarbamate of ammonium .. 18-71 do. ............ 1-091 10" 1*4171 1-4254 ...... Xanthate of potassium .......... 24-34 ao. ............ 1-106 4O 1.3891 1-3961 ...... Chlorate of potassium .......... 126.75 do. ............ 1-032 17" 1*3334 1*3376 1*3483 Bromate of potassium .......... 193.49 do. ............ 1*035 IT" 1*3341 1*3382 1-3491 Idetaphosphoric acid ............ 8.23 do. ............ 1-270 20 *5" 1-3718 1*3764 1-38'79 Orthophosphoric acid .......... 13.30 do. ............ 1,180 7 5" 1.3584 1.3630 1*3746

ISSN:0368-1769    

DOI:10.1039/JS8702300101

出版商:RSC    

年代:1870

数据来源: RSC

摘要:

XV.-Re$ea.rches on Kryptoplzanic Acid the normal free acid of Human Urine. By J. L. W. THUDICHUM, M.D. CONTENTS. 1. Mode of isolating kryptophanic acid from fresh human urine by lime and alcohol process. 2. Purification by lead acetate process. 3. Purification by copper acetate process. 4. Mode of obtaining kryptophanic acid from urinary extracts after removal of all products of decomposition of urochrome by sulphuric acid. 6. Mode of obtaining kryptophanic acid from fresh urine without intervention of heat. 6. Chemical properties of kryptophanic acid. 7. Absorption of oxygen by kryptophanic acid in alkaline solution. 8. Kryptophanates of the alkalies. 9. Kryptophanate of lead. 10. Basic lead kryptophanate.11 Eryptophanate of copper (with alcohol). 13. Kryptophanate of copper (without alcohol). 13. Kryptophanate of magnesium. 14. Calcium kryptopbanates. 16. Kryptophanate of baryum. 16. Acid baryum kryptophanate. 17. Kryptophanates of cobalt. 18. Silver-salts. 19. Theoretical considerations concerning kryptophanic acid. 1. A4ode of isolati2Lg Kryptophanic Acid frow fresh Hztmun Urine by Lime and A lcohol process. The urine is treated with milk of lime to alkalinity filtered and evaporated. After filtration from the gypsum it is acidified with acetic acid and evaporated to crystallisation. After some standing the syrup is filtered from the salt cake and is now ready for treatment with alcohol.Of this syrup one volume is niixed with four volumes of alcohol of 95 per cent. or five volumes of 90 per cent. and shaken in a stoppered bottle. A voluminous flaky adhesive dark precipitate is formed which speedily settles in the bottom of the fluid. The liquor is de- canted tlie precipitate shaken with some fresh strong alcohol and the alcohol again decanted. The bottle and precipitate THUDICHUM ON KRYPTOPHANIC ACID. are now slightly warmed when the latter gives out much alcohol which is poured away. The impure calcium salt is now dissolved in a small quantity of water filtered through a calico bag with the aid of pressure (it soon clogs any paper filter) and again precipitated with four volumes of strong alcohol.The precipitate is collected in a calico bag and freed from alcohol by pressure. It is now free from the soluble urinary ingredients. By repeating the solu- tion in water and precipitation with alcohol a few times more almost pure calcium kryptophanate can be obtained. But it is preferable to adopt one or other of the following processes of purification. 2. Purtjkation by Lead "Ac ptute. The crude calcium salt above described is dissolved in water and mixed with a large quantit>y of nearly saturated watery solution of neutral lead acetate. The mixture is shaken in a stoppered bottle and filtered. The filtrate is nearly colour- less ;a dark-coloured voluminous precipitate of basic salt remains on the filter. The latter is washed with some saturated lead solution.The united filtrates containing all the neutral lead kryptophanate in solution are mixed with five or six volumes of alcohol of 95 per cent. whereupon perfectly white lead kryptophanate is deposited in flakes. They are washed with alcohol slightly with water (for washing with much water produces basic salt) then with alcohol again lastly with ether and dried in vacuo during which they assume a slightly yellowish colour on the surface. The precipitate may also simply be washed with water to remove lead acetate the basic kryptophaiiate being also insoluble in water as well as in alcohol. By decomposition with the exact amount of sulphuric acid required the free acid is obtained and best transformed into baryum salt by baryta-water in excess and a current of carbonic acid.The baryum salt is precipitated by alcohol re- dissolved in water and again treated with lead acetate in excess. The filtrate with alcohol yields pure white krypto- phanate. (The insoluble part is hasic salt and can be used for obtaining the free acid by decomposition with an equivalent quantity of dilute sulphnric acid.) THUDICHUM ON KRYPTOPHANIC ACID 3. Pu&jkation by Coppel* Acetate. To the solution of the crude calcium salt an excess of copper acetate is added. A voluminous dirty green precipi- tate ensues and a greenish-blue solution forms which is separated by filtration. To this latter five or six volumes of alcohol of 95 per cent. are added which produce a voluminous greenish-blue flaky precipitate This is filtered and washed with alcohol and dried in vacuo over sulphuric acid.The niother-liquor must remain blue with excess of copper acetate in order to obtain all kryptophanic acid as copper salt free from calcium. This copper salt is soluble in water while moist with alcohol but insoluble in water after it has been dried. Its solution before the addition of alcohol must not be heated as in that case a change takes place as evidenced by the formation of an insoluble greenish-red precipitate. In order to obtain the free acid the copper salt must be decom- posed with sulphuretted hydrogen. 4. Mode of obtaining Kq*yptophanic Acid from Urinagoy extracts after removal of all products of decomposition of Urochrome by Sulphuric Acid.In the foregoing process applied to fresh urine the urochrome remains undecomposed in the alcoholic solution. Kryptophanic acid is therefore not a product of urochrome as is also evident from many other circumstances. In the process now to be de- scribed kryptophanic acid is obtained in large amount from the extracts from which urochrome products have been entirely removed. The extracts containing great quantities of ammonium sul- phate are nixed with excess of milk of lime filtered through cloths and boiled to drive out all ammonia. They are then acidified with acetic acid and evaporated to crystallisation. The filtered extract is treated with alcohol like the extracts from fresh urine. The precipitate contains much more potas- sium chloride than that from fresh urine and requires special care to be purified from this by one or other of the above pro- cesses.It also contains iron which follows the acid into nearly all its preparations. This is best removed by adding to the solution freed from calcium by ammonia and ammonium carbonate a sufficient amount of ammoiiiunl sulphide and filter- THE NORMAL FREE ACID OF HUMAN URINE. ing immediately. By evaporation the alkali and sulphide are removed and the solution of the ammonium-salt is ready for the application of lead acetate. 5. Mode of obtaining Kryptophanic Acid from fresh Urine without the intervention of geat. The dilute free acid and its acid salts are little affected by heat and air but its neutral and alkaline salts become dark in solu- tion or in the wet state.To avoid this objectionable effect the following process may be adopted. The filtered fresh urine is treated with lead acetate as long as this reagent produces a precipitate. An excess of neutral lead salt ia to be carefully avoided. Experience shows that to every litre of the fresh urine of healthy men 40 cubic centimetres of a solution satu- rated at 9.5OC. of lead acetate should be added and the precipi- tate produced thereby will be sulphate and phosphate exclu- sively with only a trace of organic salt. (From 1 litre of average urine 6.2 grm. of mixed lead salts are obtained.) To the filtrate more acetate and some ammonia are added. The precipitate is collected in a calico-bag pressed washed with water pressed again and then decomposed with sulphuric acid in slight excess.It is yellow and gives the spectrum of uro-chrome being a broad absorption band at the beginning of blue. The filtrate is treated with baryum carbonate and a little baryta water. The solution of baryum kryptophanate is now mixed with five volumes of nearly absolute alcohol whereupon the kryptoplianate is precipitated the urochrome remaining in solu- tion The baryum kryptophanate is dissolved in water and again precipitated with lead acetate ; the precipitate after filtration is digested with a sufficiency of saturated solution of lead acetate and the solution filtered. The filtrate is treated with five volumes of nearly absolute alcohol whereupon lead kryptophanate falls down in white flakes which should be washed with alcohol a little water alcohol again lastly with ether and dried in uacuo.(i.Properties of Kryptophunic Acid. It is a transparent amorphous gummy solid mass almost or entirely colourless. It is soluble in water in all proportions; less soluble in alcohol. Alcohol produces a precipitate in THCTDICHUM ON KRYPTOPHANIC ACID the water solution and after this has deposited ether producee a new precipitate in the mixture. It has it freely acid taste. It decomposes the carbonates of alkalies and earths with effer- vescence forming watery solutions of the salts. Its solution forms with lead acetate a copious thick white precipitate; with mercury acetate a similar Precipitate; with silver nitrate the precipitate is slight.The lead acetate precipitate forms a clear solution with excess of acetate. The solution of the free acid is not precipitated by mercury dichloride nor by copper acetate. The aqueous solutions of its earthy salts show the following reactions :-They are precipitated by excess of alcohol. On being heated they fuse and become dark ultimately dry and may be powdered after which they are very stable. Boiled with a great excess of alkaline copper solution they reduce the oxyde and form sub- oxyde which remains in solution but is deposited if the mixture is concentrated and air excluded. The alkaline solution fluo-resces blue. The watery solntions of the earthy salts are precipitated copi- ously white by lead acetate and are soluble in excess of acetate ; by mercury acetate white; by mercury nitrate voluminous white; the ordinary estimation of urea by this reagent is thus shown to be liable to error and to require a correction for kryptophanic acid which has probably increased all values obtained for urea by from 5 to 10 per cent.; by silver nitrate white voluminous.All these precipitates are slightly soluble in water insoluble in alcohol; they are soluble in nitric acid. Iodine disfiiolved in an iodide 011 being added to a solution of kryptophanic acid or of a kryptophanate produces immediately aniodo-kryptophanic acid in which one or several atoms of hydrogen are replaced by iodine. The liquid immediately coii- tains hydriodic acid.Thus on addition of tincture of iodine to fresh urine the iodine is at first precipitated as if the tincture had been added to water but is almost immediately redis- solved by substituting hydrogen in kryptophanic acid. This reaction was the subject of a lively debate in France some years ago. Bromine added to kryptophanic acid or the solutions of its salts in water immediately produces a brominated acid in which one or more atoms of hydrogen are replaced by bromine. THE NORMAL FREE ACID OF HUMAN URINE. The reaction with bromine is perhaps neater than that with iodine and the product less liable to change and decomposi-tion. The kryptophanates on being heated emit acid vapours but no urinary smell whatever is perceived like that emitted by omicholine.They then leave a quantity of charcoal which requires prolonged heating before it is entirely consumed. Kryptophanic acid prevents the precipitation of ferric oxide from solutions containing excess of caustic alkali. Like oxalic acid it holds prussian blue in solution in the presence of fkee hydrochloric acid. An ammoniacal silver nitrate solution becomes immediately very dark on addition of ammonium kryptophanate. On stand-ing it becomes apparently black (being red when diluted) and deposit's metallic silver as a black powder. Nitrate of silver and excess of nitric acid added to a solution of kryptophanic acid containing urea (to urine with little uro- chrome and much Kr such as is discharged in certain conditions of the brain intermittent spttsmodic disease) is reduced on standing and the glass is covered with a silver mirror.7. Absorption of Oxygen by Crude Kryptophanic Acid in A lkalin e Solution. A quantity of crude kryptophanate of calcium was dissolved in water to 20 c.c. and enclosed in a graduated tube over mer- cury; 47 C.C. of air were now allowed to enter the tube and after that 14 C.C. of concentrated caustic potash solution were added. After three weeks of standing the air had diminished to 38 c.c. so that 9 C.C.of oxygen had been absorbed equal to to 19.1 per cent. of the air employed. When highly purified neither the free kryptophanic acid nor its baryum salt with excess of baryta water seem to absorb pure oxygen over mercury.8. Kryptophanates of the Alkalies. These salts are very soluble in water. The sodium-salt is not precipitated from its aqueous solution by alcohol. TRUDICHUM ON KRYPTOPHANIC ACID 9. Kryptophanate of Lead C,H7PbN0,. Crude calcium kryptophana te precipitated by alcohol was mixed with excess of a saturat'ed solution of lead acetate and filtered from the precipitate of basic kryptophanatc. The solution was mixed wit11 five volumes of alcohol of 95 per cent. The precipitate of kryptophanate a white flaky mass thereby produced was washed with alcohol water alcohol and ether in succession and dried in vacuo. It darkened during the washing and ultimately became pale yellowish. When quite dry it had shrunk very much and acquired a dark colour.Analysis (dried in vac~.co):-I. *3996grm. with H,SO and ignition yielded 03104 PbSO, equal to 53.07 per cent. Pb. The formula C,H,NPbO .+ aq. requires 53-62 per cent. Pb. The above lead salt which had been kept over sulphuric acid was now further dried at 105'. (Exposed to the air this salt absorbed nearly the whole of its water and on again drying lost it again.) Analysis of the salt dry at 105" I. 05900 yielded ~4820grm. PbSO, which allowing *0008 for correction gives 55.72 per cent. Pb. IT. Combustion-1.3905 burned with CuO etc. gave 02363 H,O and *800 CO, equal to 1.89 per cent. K and 15-69 per cent. C. 111. Nitrogen determination-*7 708 grm. burned gave gas equal to 21.48 C.C. normal (i.e. at Oo 760 mm. and dry). After oxygen and pyrogallate of potassium it gave gas = 13-97 C.C.normal therefore nitrogen = 17.73 c.c. or 0.2226 grm. or 2.89 per cent. IV. -5847 gave 04760 PbSO, equal to 55.73 per cent. Pb. / Calculated. A * /-I. 11. Found,/ 111. 1v.- 5C ...... 60 16.30 - 15.69 - I 7 H...... 7 1.90 c 1.89 - I Pb...... 207 56-25 55-72 - - 55-73 N...... 14 3.80 - - 2-85 I 5 0 ...... 80 21-75 -.- 363 100*00 THE NORXAL FREE ACID OF HUXAN URINE. 10. Basic Lead Kryptophanate. When the iieutral salt is washed with water for a long time it loses one-third of its acid and there remains behind a salt having the composition 2(C ,H,,Pb,N,O lo) PbO. Theory. Found. A Y c A \ I. 11. IIT. 20 C .... 240 14.16 13.05 -28H .... 28 1.65 1.75 -5 Pb.... 1035 61.06 -61.2 60.61 4N .... 56 210 .... 336 -1695 Note.-Analyses 1and 2 on the same preparation. Analysis 3 on sample prepared in another operation. 11. Kyyptoplzanate of Copper (with alcohol). Prepared by adding a great excess of copper acetate to a solution of the calcium or sodium salt filtering and precipi- tating the filtrate with much alcohol washing with alcohol and drying in the steam-oven powdering drying in vacuo. Pre-pared in this way the salt is a compound of kryptophanate with alcohol. Analyses :-I. Combustion with oxide of copper a little potassium chlorate and copper turnings. 1.2771 burned gave -5305 H,O and 1.3555 CO equal to 4.62 per cent. H. and 28-95 per cent. C. 11. -4885 burned as I gave ~2100H,O and *5290CO equal to 4.67 per cent.H and 29-53 per cent. C. 111. ,7235 burned and treated with HNO gave *2192CuO equal to 24-20 per cent. Cu. IV. *4470 gave CuO ,1384 equal to 24.67 per cent. Cu. V. In this analysis 24.18 per cent. Cu were obtained. THUDICHUM ON KRYPTOPHANIC ACID Found. I. 11. 111. IT. V? C ...... 28-95 29-53 - - I H ...... 4.62 4.67 - - - cu.. .... - - 24.20 24-67 24-18 The analyses lead to either 2(C,H,NCuO,) + C,H60 + H,O. 2(C,H7CuN0,) + C,H,O or 12. Kryptophanate of Copper (without alcolhol) C,H7CuN0,. If the foregoing salt is exposed to moist air and then dried in wacuo it loses aZcoho1 and at the same time changes in colour becoming very dark green. Analysed in that state it yields results corresponding with the formula C,H,NCuO,.Analyses :-I. Combustion with copper oxide potassium chlorate and Cu. -2859 gave *2840 GO, equal to 27.09 per cent. C'(water not weighed). 11. Nitrogen determination-*4016 gave 00255grm. of N. equal to 6-35 per cent. 111. 01752 grm. gave *0603CuO equal to 27.50 per cent. Cu. IV. Dried at 120" -4077 left ,1455 CuO equal to 28.82 per cent. cu. Calculated. C ...... 60. 26-72 H ...... 7. 3-12 Cu ...... 63.5 28-29 N ........ 14. 6.24 0 ...... 80. 35.63 224.5 100*00 Dry Distillation of Copper Salt.-8-25 grm. of this salt was subjected to dry distillation and yielded first water which was removed from the receiver; then on stronger heating a white heavy vapour came over which was alkaline smelled of cyanide and of tobacco and crystallised in white crystals on cooling.It THE NORMAL FREE ACID OF HUMAN URINE. 125 was perhaps cyanide and cyanate of ammonium effervesced with platinum tetrachloride and gave a crystalline salt ;it was accom- panied with a dark red oil which when mixed with HC1 and PtCll reduced the platinum and gave a rather black solution. The oil was more soluble in ether than the crystals BO that a separation could be thereby effected. 13. Kryptophnnate of Magnesium. Free acid prepared by the decomposition of wet lead-salt by means of an equivalent of dilute sulphuric acid was treated with an excess of magnesia filtered and the filtrate evaporated on the water-bath. The salt formed a mass like treacle which was dried up powdered and dried at 110' to 120".Analyses :-I. 05363grm. ignited gave -1023 grm. MgO equal to 11.43 per cent. Mg. 11. Dried at 125' for some time 0508 grm. salt left after com-bustion 0100 gym. MgO equal to 11.8 per cent. Mg. 111. -4653 grm. gave -0893 MgO equal to 11.51 per cent. Mg. IV. 05232 grm. gave -03484 grm. nitrogen equal to 6.66 per cent. N. Calculated. Found. -/ *-A \ I. 11. 111. IV. 1OC...... 120 29.56 --14H .... 14 ---2 Mg.. .. 48 11.83 11.45 11.81 11.51 -2N .... 28 6.90 -6.66 c 10 0.. .... 160 2Aq .... 36 -406 Dried at from 140' to 160" it lost an atom of water and became C,,H,,Mg,N,O, +Aq. Theory. Found. P c \ I. 11. 30.93 C 31.01 - 4.12 H 4.78 - 12.37 Mg 12.12 I VOL.XXIII. L 12a THUDICHUM ON KRYPTOPHANICI ACID I. Combustion *3650grm. gave *1570 grm. H,O and 0415 CO, equal to 4-78 per cent. H. and 31-01 per cent. C. 11. 04690 grm. gave -0948 grm. MgO equal to 12-12 per cent. Mg. 14. Calcium Kryptophanates. Some fiee acid was made by decomposing lead salt with an equivalent of dilute H,SO (a little baryta water was added to remove a slight excess of sulphuric acid). An excess of milk of lime prepared from lime which had been washed was added to the acid and the niixture boiled and filtered. To the filtrate about an equal volume of strong alcohol was added and a precipitate obtained. This was dried in the water-bath further dried at llOo and analysed.I. 06242grm.gave ,3152 grm. CaSO, equal to 14.85 per cent. Ca. Further dried at 170'. 11. 02845grm. gave 01465grm. CaSO, equal to 14-92 per cent. Ca. 111. 06240grm. burned with lead chromate gave 07542CO equal to 33-14 per cent. C. The Jiltrate was evaporated to dryness and the lime-salt powdered and dried at 135'. Analysis :-IV. 0348grm. gave -2002 grm. CaSO, equal to 16.94 per cent. Theory. Found. / A \ A > 1. 11. 111. IT. 7 10 C .... 120 32.88 -33.14 -13H .... 13 -$ Ca.. 60 16.43 14.85 14-92 -16.95 2N .... 28 90 ....-144 365 When kryptophanic acid is boiled with excess of milk of lime there is produced a salt containing 8 of Ca to 1of acid. This salt has considerable stability but appears to be very slowly THE NORMAL FREE ACID OF HUMAN URINE.attacked by the CO of the air. If however the salt be dried up and then powdered one-third of the calcium pames into car- bonate and the dibasic salt Cl,H14CaN,09 icJ produced (just a8 in the case of the Ba salt). 15. Kryptophanate of Baryuna. The magnesium salt was precipitated boiling with slight excess of hydrate of baryum filtered and evaporated nearly to dryness in the water-bath; refiltered and the filtrate dried in the water-bath. It formed a perfectly translucent red-brown varnish. Dried at 110O. Analysis :-I. 0445grrn. gave -338 grm. BaSO, equal to 44.66 per cent. Ba. CloHl,Ba2N,0, + Aq. requires 44-62 per cent. Ba. This salt took up CO of the air and formed a deposit of BaCO,.The solution on evaporation to dryness left a residue which dried at llOo,contained 36.28 per cent. Ba. It would also seem that there is a baryta-salt of the formula C,oH15Baal'u'2O,0' 16. Metamorphosis of Barywm Kryptophanate into an Acid Salt by boiling with water. 15.5 grammes of copper kry-ptophanate (containing a certain quantity of alcohol) was decomposed with hydrogen sulphide and filtered. The filtrate was boiled for a long time with baryum carbonate and some baryum hydrate and gave off a smell of ammonia. It was subsequently filtered. The precipitate on the filter contained much carbonate and probably an organic pro- duct of decomposition. The filtrate was mixed with a large quantity of 98 per cent. alcohol whereupon a pale yellowish white baryum salt was precipitated.This salt was washed with alcohol of 98 per cent. (the wash-alcohol was strongly alka- line) dissolved in water and the aqueous solution boiled. Thereupon ammonia was again perceptible and an abundance of baryum carbonate precipitated. This was removed by filtration the filtrate evaporated to dryness at 110" and powdered. It THUDICHUM OM KRYPTOPRANIC ACID formed a gummy mass offering no difficulty to comminution. The total amount of baryum salt obtained was 4.377 grms. Analyses :-I. 05170 grm. burned with lead chromate and copper turnings gave 01800 H,O and 05090CO, equal to 3.87 per cent. H. and 26.94 per cent. c. 11. *4025 grm. gave 002391 grm nitrogen equal to 5.94 per cent N. 111.*2700 grm. dried at llOo and burned left -1458 BaSO, equal to 31.75 per cent. Ba. These data lead to the formula C,,H,,BaN,OS Calculated. Found. / -I. IT. 111. -10 C ...... 120 27.09 26.84 --14H ...... 14 3.16 3.87 -e Ba .... 137 30.93 -31.75 2N ...... 28 6.32 -5.94 -9 0 ...... 144 32.50 443 100~00 The reaction by which this salt is produced is the loss of baryum oxide. Thus C H Ba N 0 + C H Ba N 0 This salt gave a white precipitate with silver nitrate soluble in nitric acid. It gave a white precipitate with lead acetate soluble in acetic acid. It gave no reaction with copper acetate zinc chloride or calcium chloride. With corrosive sublimate it gave a white precipitate soluble in HNO ; with mercuric nitrate the same ; with mercurous nitrate a precipitate which apparently white at first became quickly dark.The solid baryum salt moistened with strong sulphuric acid appeared to give a double sulphate and kryptophanate of baryum THE NORMAL FREE ACID OF HUMAX URINE. 17. Kyyptoplzanates of Cobalt. A solution of kryptophanic acid (some of the same sample as that employed for magnesium salt) was treated with cobalt carbo- nate; effervescence ensued in the cold and more on boiling. A red solution was obtained and precipitated by two volumes of alcohol of 94 per cent. A pale pink precipitate ensued which was filtered off. On drying in the steam-bath it shrunk then fused like the calcium and other salts and soaked the paper like fat (of' this the greater portion dissolved in waxm water with red colour as before).It ultimately became hard and then wag white rose coloured in the interior of the lumps. It was powdered and dried at 100" to 110". Determination of Co.-.0834 grni. burned and reduced in H atmosphere gave *014grm. or 16-78 per cent Go. The formula C,,H16CoN,0, (M.W. 382.8) requires 15.36 per cent. Go. The formula Cl,H,,CoN,09 requires 16-19 per cent. Co. Xolution in AIcol~oZ.-Was of a rose red colour and on evapora- tion in platinum dish became indigo blue wherever it dried and was ultimately a deep blue hard mass. It was redissolved in water when it again became red; filtered from slight precipitate and again evaporated. Dried at 110". On heatmg it swelled up greatly gave out stinking gas and left residue of cobalt and carbon.This had to be treated with nitric acid to deflagrate all carbon after which the cobalt was reduced in hydrogen atmo-sphere. Determination of CobaZt.-*2897 grm. left after the before men-tioned treatment -08 grm. Co or 27.7 per cent. Go. The for-mula Cl,H,,Co,N,Ol (M.W. 439.6) requires 26.7 per cent. Co. C,,H,,Co,N,09 requires 27.9 per cent. Co. 18. Silver-salts. When a solution of a tetrabasic kryptophanate as for instance the magnesium salt C10H14Mg2N2010, is mixed with a solution of silver nitrate there is produced a dark grey pre cipitate which either has not a definite composition or else suffers decomposition spontaneously or on washing. The fol- lowing determinations of silver in different specimens of the precipitate will serve to illustrate the inconstancy of its comps.sition after having been wmhed and dried. THUDICHUM ON ERYPTOPHANIO ACID Percentage of silver. Precipitate a ................ 77.2 Do. b ................ 60.08 DO. c ................ 56.56 Preciptate a was prepared by using a very small proportion of silver nitrate to precipitate the magnesium kryptophanate. It was washed dried in the steam-bath and finally dried at looo to 110" Precipitate b was washed six times with a small quantity of water and dried in vacuo. Precipitate c was very little washed and then pressed and dried in vacuo for several days.- Thus it appears that by dint of washing decomposition of the silver-salt is effected so as to give a salt richer in silver than the original precipitate.Precipitate c which may be regarded as the least altered specimen of the precipitated silver-salt roughly approximates in composition to the formula Cl,Hl,Ag4N,010 +2 Aq. corre-sponding with the magnesium-salt fiom which it was formed. The following are the details of its preparation and analysis:- 3 grm. of silver nitrate were dissolved in water and precipita- ted with 8 C.C. of very concentrated solution of tetrabasic magne- sium kryptophanate. The dark-coloured precipitate after slight washing pressing and drying in vacuo for several days weighed 1.603 grm. I. -8455 grm. burnt with copper oxide etc. gave -4055 grm. of CO (water not weighed). 11. *4300grm. gave *2432 grm.of metallic silver (by ignition after moistening with nitric acid). The formula C,,H14Ag4N,0, +2 Aq. requires Calculated. - Found. r A 1OC .......... 120 15.2 13.08 18 H.. ........ 18 c - 4 Ag ........ 432 54.7 56-56 2 N .......... 28 12 0 .......... 192- 790 (It will be understood that the insufficiency of the washing would occaeion the carbon to be too low and the ignited resi-due to be too high for the real quantity of silver.) THE NORMAL FREE ACID OR' HUMAN URINE. The interpretation which is to be put on the data given by this examination of the silver-salt appears to be the following. The tetrabasic silver-salt is very perishable and breaks up into tribasic silver-salt and silver oxide. By washing tribasic silver- salt is more or less perfectly dissolved out and silver oxide accordingly accumulates in the precipitate.The stable silver-salt of kryptophanic acid appears to be the tribasic salt and is formed by double decomposition when either a dibasic or a tribasic kryptophanate is added to a solution of silver-nitrate. It is white and appears to be rather soluble in water. a. Some silver-salt obtained by double decomposition between dibasic calcium-salt and silver nitrate was washed and dried in vacuo. -1110 grm. gave *0570 grm. of metallic silver or 51.35 per cent. Ag. b. Some silver-salt prepared from dibasic baryum-salt and ailver-nitrate and dried in vacuo gave 52-80 per cent. Ag. c. Another quantity of silver-salt made from a specimen of calcium kryptophanate believed to be the tribasic salt had the following history :-Calcium kryptophanate purified twice by resolution in water and precipitation by alcohol was boiled with animal charcoal to decolorize it and then mixed with silver nitrate as long as a precipitate was produced.The precipitate white at fist became slightly coloured grey. It was washed ultimately boiled with alcohol and driedat 100" to 110'. At 130"it became brownish on surface. Analyses :-I. 02785grm. left ,1479 grm. or 53.1 per cent. Ag. 11. *3722grm. left -2005 grm. or 53.86 per cent. Ag. 111. 52.8 per cent. Ag. found. IV. -2048 grm. burned with CuO Cu and KClO, yielded .150 of CO and *046H,O equal to -0409 grm. or 19-97 per cent. C. and 00051grm. or 2-49 per cent.of H. V. 02656grm. burned with CuO and Cu gave gas = 16.1 C.C. at 12.5O and 641-2 mm. (dry) equal to 13. C.C. absolute. Cor-rected with 0 for NO this became 12. C.C. absolute equal to ~01507grm. or 5.7 per cent. N (roughly). THUDICHUM ON ECRYPTOPHANIC AOID. Calculated. Found. -A -/ r a. b. I. 11. 111. IT. V. 10C ........ 120 19.08 ---19-97 - 13H ........ 13 2.07 ---2.49 - 3 Ag .,. . ,. 324 51.53 51-35 52.80 53.1 53.8 52.8 -2 N ........ 28 4.45 -- - -5.7 9 0 ........-144 62 9 19. Theoretical considerations on Kryptophanic Acid. Kryptophanic acid is wrilten in much of the foregoing as a dibasic acid of the formula C,H9N0,. But it is evident that it may be considered as tetrabasic and to have the formula Cl,H,,N,Ol,.In that case the metallic salts will have the gen era1 formula C ,H 14M'bN20,. Examples :-Lead-salt .............. C,,H14Pb,N,0,,. Do. hydrated.. .......... Cl,H14Pb2N,01 + 2Aq. Basic ................. 2(Cl,H14Pb,N,01,)Pb0. Copper salt ............ Cl,H14Cu,N,0,,. Do. with alcohol ........ Cl,H14Cu2N,01 + C,H60. Magnesium salt. ......... Cl,H14111g,N,010 + Aq. Do. dihydrate .......... CloH~4Mg2N~Olo + 2Aq. Baryum salt ............ C,,H,4Ba,N,01 + Aq. Do. tribasic ............ C,,H 13ba13N,0 Do. acid ................ C,,H,,BaN,O,. Calcium salt ............ Cl,H13ca13N,0,. Do. acid ............... C,,H14CaN,0S. Co balt-salt acid. ......... Cl,H,4CoN,0g. Do. basic .............. C1,B12C~,N2Og. Silver-salt ..............Cl,H13Ag,N,09. It gives me great pleasure to acknowledge the important aid which I have received from my friend Mr. J. A. Wanklyn in the latter part of this research more particularly inthe elucida- tion of the changes of basicity of several salts. My thanks are also due to my assistant Mr. C. G. Stewart for the care and assiduity with which he prepared for me large quantities of the primary material. The foregoing research has been conducted by me for the Medical Department of the Privy Council at the Pathological Laboratory of St. Thomas's Hospital.

ISSN:0368-1769    

DOI:10.1039/JS8702300116

出版商:RSC    

年代:1870

数据来源: RSC

摘要:

133 By W. H PERKIN,F.R.S. INthe remarks I have the honour of bringing before the Society I thought it as well not only to give an account of what is actually new in reference to my subject but at the same time though in a very brief manner to refer to a few points in the chemical history of alizarin and the reseaches which led to its artificial formation. Alizarin was first obtained from madder in a crystalline con- dition by Robiquet and Colin but the method they adopted for its preparation viz. sublimation rendered it a matter of uncer- tainty whether alizarin pre-existed in that substance or was a product of the decomposition of some other body. Dr. Sc hu n ck however after much labour succeeded in obtain- ing it in a well crystallized state without having recourse to sublimation.There has been a great deal of controversy respecting the formula of alizarin Schunck contending for that which he first gave viz. C,,H,,O, whilst Strecker believed it to be C,,H60, and related to Laurent’s chloroxynapthalic acid rJince both these substances yield phthalic acid by decompo- sition with nitric acid. In fact chloroxynaphthalic acid was regarded as chlorinated alizarin the two bodies being thua related. C10H603 ClOH,~O Alizarin or Oxynaphthalic acid Chlorinated alizarin or Chloroxynaphthalic acid. Of these formulae Strecker’s became the favourite one. About five years since Martius and Griess when investigat- ing the amide derivatives of naphthol obtained a colouring matter possessing Strecker’s formula.This however was not alizarin but was regarded as an isomer of that body.* Some time after the discovery of this supposed isomer of alizarin Charles Graebe commenced his research on quinone. * Annalea der Chdmie und Pharmacie cxxxiv p. 375. Bull. Chem. SOC. Paria iv p. 389 VOL. XXIII. M PERKIN ON ARTIFICIAL ALIZARIN. This substance was discovered as early as 1838 by Woskres- ensky as a product of the oxidation of quinic acid and although investigated by ninny chemists as Wijhler Laurent Hofmann Stenhouse and others no clue to its chemical structure had been obtained. Kekul6 however expressed the opinion that it might be a compound containing carbonyl and represented thus :-CO-CH-CH=CH-CH=CO CO=C4H4=C0.Graebe after working with great energy upon quinone com- pounds came to the conclusion that it is not constituted accord- ing to the above formula but is a substitution-product of benzol in which two atoms of hydrogen are replaced by the group (0-0)") in which half tho combining valuea of oxygen saturate each other,* thus :-C6H6 C6H4 (''2)" Benzol. Quinone. The best known derivative of quinone is perhaps chloranil or perchloroquinone. This is obtained by heating phenol wit,h potassic chlorate and hydrochloric acid its composition being C,C140, or C6C14(0,)f1. When heated with alkalies it gives up two atoms of chlorine and forms potassic chloranilate or dichloroquinonate. C6Cl,(02)f' + 4KH0 = C6C1 KO + 2KC1 + 2H,O r:: Chloranil. Potassic chloranilate.When G ra eb e commenced his researches no analogous sub-stance to qninone connected with any other hydrocarbons than benzol was recognized; but after observing the relation of this substaiice to its hydrocarbon this chemist was induced to view L a ur en t ' s chloride of chloroxynaphthyl as the dichlorinated quinone of naplithalin ; bicliloronaphthoqiunone thus :-C,OI%3 CI,H,Cl,( 0,)" Naphthalin. Bichloronaphthoquinone. * Bull POC.Chim. PariB xi p. 323. PERKlN ON ARTIFICIAL ALIZARIS. This napthalin derivative when heated with caustic alkalies behaves in a somewhat similar manner to chloranil part of the chlorine being removed; but in this case the reaction is limited to one atom of chlorine. G',,H,Cl,(O,)lf + 2KH0 KCl + H,O Dichloronaph thoquinone.Potassic chloroxynaphthalate. The acid obtained from this salt which has been assumed (as already stated) to be chlorinated alizarin is a colouring matter dyeing woo1 a scarlet or orange colour but Bas no affinity for alumina mordants. Jointly with M. Borgmann Graebe obtained chlorinated quinones of toluol by heating cresylic acid with chlorate of potassium and hydrochloric acid. The following are the products obtained in this manner :-Trichlorotoluquinone. Dichlorotoluquinone. After it had been shown that chloroxynapthalic acid was a quinone acid Graebe and Liebermann thought it probable that alizarin belonged to the quinone series; but before this could be proved it was necessary to get some clue to the hydrocarbon to which it is related.To obtain this information natural alizarin was taken and heated with powdered zinc according to Raeyer's method of reducing aromatic com-pounds. In this manner they obtained a substance having the composition C,,H,O* This hydrocarbon formed a red compound with picric acid and in fact possessed all the properties of anthracene as obtained from coal tar. Graebe and Leiberizlann did not allow this discovery to rest and reasoning from the infoimiation which had been ob-tained by the study of the quinones they asaumed alizarin to be the quiiione acid of anthracene thus- MZ PERKIN ON ARTIFICIAL ALIZARIN. Anthracene. An thraquinone. Anthraquinonic acid. Alizarin. It will be seen that this formula C,,H,O corresponds closely to that persisted in by Dr.Sclinnck differing only by H,. Having obtained anthracene from alizarin it now remained to produce alizarin from anthracene. The first step in this procc?ss was to obtain the quinone. Many years ago L aur e11 t obtained an oxygenated derivative of anthracene and named it anihvacenuse. Dr. Ander s on re-examined this body and gave it the formula C,,H,02 and called it oxanthracene. Qraebe and Liebermann at once recognized this as the desired quinone of anthracene or anthraquinone ; it therefore only remained to convert this into the acid by replacing two atoms of its hydrogen by hydroxyl and thus settle the ques- tion as to whether alizarin be the quinone acid of anthracene or not.For this purpose anthraquinone was heated with bromine and by this means dibromanthraquinone was obtained. I have referred to the decomposition of chloranil or tetrachloro-quiiione by potassic hydrate how two atoms of chlorine are removed and potassic cliloranilate is formed. It was there-fore probable that dibromaiithraqixinoiie would decompose in a similar manner when treated with this re-agent. No decompo-sition however was found to take place until a teinperature of about 180." C. was employed. The mixture of dibromanthraqui- none and potassic hydrate then changed colour becoming blue and more and niore intense and when dissolved in water was found to be an alkaline solution of alizarin which when acidi- fied deposited this product as a yellow precipitate.The reaction may be writt,en thus :-Dibromanthsquinone. Potmihie alizsrate. PERKIS OX XRTIFICIXL ALIZARIK. The latter product when heated with hydrochloric acid yielding hydric alizarate or alizarin. HO Thus Graebe and Liebermann succeeded in producing alizarin from anthracene and have given us the first instance of the artificial formation of a vegetable colouring matter. The great importance of alizarin as a dyeing agent rendered it desirable to turn this beautiful discovery to practical account and if possible render alizarin fi*om anthracene a substitute for madder. The use of bromine in Graebe's and Liebermann's process rendered it however somewhat difficult to carry out on a manufacturing scale; therefore it was necessary to find a cheaper and more manageable reagent which might be used in its stead.It is well known that sulphuric acid forms with many organic bodies compounds called sulpho-acids. In composition these simply correspond to the substance acted upon plus sulphuric anhydride the basicity of the product (if derived from a neutral body) increasing with the number of molecules of sulphuric anhydride used in its formation. It is fouid however that these so-called sulpho-acids are nothing more than acid sulphites ; and we find sulpho-benzolic acid aiid clisulpho-naphthalic acids are thus constituted :-c,~,so,= C6H,Hs03. C10H82S03 = CioH6 Sulphobenzolic Phenyl sulphurous Disulpho Naphthylene acid. acid. naphthalic acid. disulphurousacid.The experiments of W iirt z and K ekul6 have confirmed this view of the constitution of these acids. They found that sulpho- benzolic acid when heated with potash produced a phenate and sulphite thus C,H,Hso + 3KH0 = C,H,KO 3. &so3+ 2H,O. Sulphobenzolic acid. Potassic phenate. 31. DIIsar t also fouiid that d~sulphonaplit'rialic acid yielded in the same may a naphthylena-te and a sulphite. PERKIX O?; ARTIFICIAL ALIZARIN. Disuiphonaphthalic acid. Potas& naphthylenate. By the addition of an acid to the product of these reactions we obtain first from benzole by means of the sulpho-acid phenic acid or hydrate of phenyl and from naphthalin naphthylenic alcohol or dihydrate of naphthalyne C6H6 C,H,HO Benzol. Hydrate of phenyl.Naphthalin. Dihydrate of Naphthylene. We thus see in the second example that we have obtained a body standing to naphthalin as alizarin does to anthraquinone. It therefore appeared probable that if a disulpho-acid of-' anthraquinone could be found alizarin might possibly be obtained by a similar proceas. The formation of a sulpho-acid of anthraquinone however did not at first appear very probable on account of the remarkable stability of this compound ; nevertheless after numerous experiments it was found that when heated strongly with sulphuric acid it disappeared the mixture at last becoining perfectly soluble in water a sulpho-acid having formed. The analysis of salts of this new acid showed that it possessed the formula- and was therefore the desired disulphanthraquinonic acid.This substance when heated wit,h potassic hydrate to c? temperature of about 180" C. becomes coloured and when the reaction is complete the product is found to contain a sulphite and alizarin. The reaction being as follows:- + GKHO = C1,H6 2I<,SO + 4H20. L)isulphanthraquinonic acid. Potas sic alizar ate The alizarin thrown down from this alkaline product is generally of a bright yellow colour and quite w pure as the analogous precipitate obtained when dibroiiianthracluinone i,s employed. The forniatiou of alizarin however is not the primary result PERKIN ON ARTIFICIAL ALIZARIN. of the action of potassic hydrate upon this sulplio-acid an inter-mediate body being first produced. This may be called sulpho- xanthraquinonic acid ; its formation may be thus expressed Disulphanthraquinonic acid.Potassic sulphoxanthraquinonicacid. This substance is crystalline and of a yellow or orange colour ; it is easily soluble in water and produce with caustic alkalies violet or blue solutions. When heated with potassic hydrate it decomposes yielding alizarin and sulphwoua acid. We have thus the following series of bodies :-Disulphanthraquinonic acid. HSO, { PO C14H6 " hlphoxanthraqubonic acid.' Dioxanthraquinonic acid (alizarin). I may here mention that while these experiments were in progress JIM. Caro Graebe and Liebermann were in-vestigating the same reactions 111 Germany and having obtained analogous results we have agreed in ftiture to work together on this subject.We find that the process just described may be modified to some extent by first forming a clisulpho-acid of anthracene and then by meaiis of osicliaing agents converting this into the disulphanthraq~~inonic acid. In the conversion of clisulplioantl~~aquinoiiicacid into ali- zariii by the action of potassic hydrate a peculiar reverse action takes placc to a small extent both anthraquinone and aiithracene beiug formcd. This is evidently due to a reducing action similar to that which takes place ivlieii alizarin is heated with powdered zinc thus :-* This substance has not been analysed as yct but from its formation and decom-position with caustic alkalies there can be but little doubt that the tihove formula represents its qomposition.PERKIN ON ARTIFICIAL ALIZARIN. C,,H,O + 2HH = C,,H,O + 2H20. Alizarin. Anthraquinone. C,,H,02 + 3HH = C,,H, + 2H20. Anthraquinone. Anthracene. The colouring matter obtained either by Graebe and Lie- bermann’s original process or from the sulpho-acid of apthra- quinone I have invariably called alizarin. The identity of this substance with the alizarin of madder has however been called in question. I have therefore made some experiments upon this subject and carefully examined these two products side by side. For this purpose I have employed both purified sublimed and unsublirned artificial alizarin,* and for compai-ison purified sublimed alizarin prepared from madder extract. I find that both the natural and artificial bodies crystallize in needles which are usually curved especially when small.When dissolved in caustic alkali they both form violet solu- tions of the same tint. When applied to mordanted fabrics they produce exact’ly the same colours bearing the treatment with soap equally. They also possess the same tinctorial value. When_dissolved in alcohol they produce with cupric acetate a purple solution of precisely the same shade of colour. When examined with the spectroscope their potassic solutions produce the same absorption bands. Lasily the ordinary precipitated artificial alizarin yields phthalic acid when decomposed with nitric acid. I know of no other well-defined reaction of alizarin and therefore judging from these we are bound to consider artificial and natural alizarin as identical.Artificial alizarin has been objected to as a substitute for madder on the ground that pure alizarin will not produce madder colours other colouring matters being required. Now the only colouring matter in madder besides alizarin which is not injurious to the beauty of the colours is purpurin. This substance differs from alizarin in many of its properties 3% To purify the sublimed artificial alizarin it was dissolved in aqueous ammonia and after filtration precipitated with hydrochloric acid The precipitated colouring matter was then washed dried and crystallized from alcohol several times. The unsublimed product was purified with alumina by a process similar to that described by Dr.Schu n ck for the separation of alizarin from madder. PERHIN ON ARTIFICIAL ALIZARIN. 141 for example it dissolves in alkalies with a bright red colour alizarin giving a beautiful violet solution under these circum- stances. It dissolves in a solution of alum forming a pink solutioii with a yellow fluorescence alizarin is nearly insoluble in this menstruum. Its optical properties are also very marked and distinct from alizarin. This is especially the case with it8 solution in alum which gives two absorption bands when viewed with the prism in the green portion of the spectrum alizarin giving none. Professor Stokes has shown that these differences are so distinct that it is possible to detect purpurin and alizarin in a portion of madder not exceeding in bulk the fraction of a pin's head.Therefore the detection of either of these colouring matters on a piece of madder print is not difficult. Dr. Schunck remarks" that after a long course of experi-ments he has been led to the conclusion that the final result of dyeing with madder is simply the combination of alizarin with the various mordants employed and recommends the extraction of alizarin from madder prints as the easiest method of preparing it in a state of purity on the small scale. I have made some experiments also in this direction and have found nothing but alizarin on finished madder prints. I could not detect purpurin even with the spectroscope. This fact may be seen in a practical manner by removing the mordants from a madder print with hydrochloric acid and treating the colouring matter upon the cloth with a solution of potassic hydrate.It will then be found that a blue violet solution is produced of the same shade as that given by pure alizarin. If purpurin were present in appreciable quantities this would not be the case as the solution would then more and more approach purple in colour according to the percentage of this colouring matter. I do not mean to affirm that purpurin never exists on prints dyed with madder or garancin as there are several classes of goods produced in print-works and sub- jected to more or less soaping &c. Some styles of garancin work are I believe not soaped at all or only slightly the whites being cleared with dilute chloride of lime There can be no doubt that the higher the class of print and the more brilliant the colours the purer is the alizarin in combi- nation with the mordants.I have already referred to the absorptiou spectra of alizarin * Jour Cbem SOC,~ VO~.xii p. 202. PERRIN ON ARTIFICIAL ALIZARIN. and purpurin. There is however a third substance mentioned in this paper to whose special character I must refer as under certain circumstances it gives an absorption spectrum so like alizarin that it niay easily be confounded with that body when examined with the prism. I refer to sdphoxanthraquinonic acid-It will be seen from the following woodcut that when dis- solved in alcoholic potush this substance gives two absorption bands in nearly the same position as alizarin when examined under like conditions.It may however be distinguished from this body by the examination of its solution in aqueous potash this giving a third absorption band near to E which although not dark is very distinct. Alizarin in aqueous potash produces a more general absorption and the bands are not so sharp as when alcohol is used; a third band is also seen in this case according to Professor Stokes but so feeble that it is almorJt lost in the general darkening. In chemical properties sulphoxanthraquinonic acid differs essentially from alizarin it being soluble in water and insoluble or nearly so in ether ; alizaiin behaving in an opposite manner to these solventa. Aa 5C D E3 F C I. dlizarin in alcoholic potash.11. Sulpiioxanthraquinonic acid in alcoholic potash. ITI. Sulphoxanthraquinonic acid in aqueous potash. JV. Purpnrin in sulphate of alumina. PERKIN ON ARTIFICIAL ALIZARIN. 143 Arti'ficial alizarin as supplied to the dyer and printer is not chemically pure and nsually produces with alumina-mordants colours somewhat redder than niadder. It has been stated that this is due to the presence of pnrpurin; this however is not the case as none of this colouring matter can be detected even by Professor Stokes's test; Dr. Schunck has-also con-firmed this .* The shade of colour produced with artificial alizarin may be modified to some extent by regulating the temperature of the dye-bath the colours on the alumina mordants being nearer to those produced with madder when a low temperature is em-ployed.The redder shade produced with this colouring matter is however often preferred especially for Turkey red dyeing. The quality of the colouring matter appears to be under the control Gf the manufacturer to a considerable extent and it is possible that eventually artificial alizarin will be prepared in a nearly chemically pure state. A good deal has been said about anthracene it being assumed that it cannot be obtained in large quantities. It must be remern- bered however that tar distillers have had as yet but little experience in separating this substance ; but from experiments 1 have made upon this subject I am led to believe that coal tar contains considerable quantities of this hydrocarbon.There can be no doubt that the kind of coal as well as the tempera- ture employed in the gas works influences the quality of the coal tar as a source of anthracene but upon these points no definite inforniatioii has been obtained up to the present. The patterns opposite the first page are dyed with artificial alizarin prepared from anthracene by the new process described in this paper. * Of the impuritiesof artificial alizarin little is known as yet. Dr. Schunck has examined some residues I lately sent him containing a considerable quantity of these bodies and has isolated a beautiful yellow substance crystallising in golden scales when sublimed and not unlike rubiacin except that it forms with alkalieg a yellow instead of a red solution.This substance has no affinity for mordants. When purifying artificial alizarin by converting it into an alumina lake I found that upon digestion with carbonate of potash this lake gave a red-coloured solution containing a colouring matter dyeing mordants very similarly to alizarin with this difference that the reds were more scarlet and the purples bluer or more slaty. I have not obthined this body in it perfectly pure state as yet but it appears to Le crystalline. It gives two faint black bands when examined in alkaline solution with the prism but these may perhaps be due to the presence of traces of alizarin.

ISSN:0368-1769    

DOI:10.1039/JS8702300133

出版商:RSC    

年代:1870

数据来源: RSC

摘要:

By JOHN M.A. F.C.S. F.R.S.E. Chemical Assistant HUNTER Queen’s College Belfast. THEpresent paper niay be considered as a sequel to that read before the Cliemical Society in December last on the analysis of sea water performed on board H.M.S. “ Porcupine.” Since that time I have examined the composition of the water taken from various depths. Iu coilsequence of the very small a,mounts of the samples which remained after obtaining the quantity of the gases held in solution and the organic matter it was only possible to determine the more important substmces con-tained in them and unfortunately the proportion of‘potassium at the different depths coiild not be observed. The valuable researches of Professor F orchanimer on the composition of sea-water from differeiit parts of the ocean were communicated to the Royal Society in a paper read November 17th 1864.He procured a number of specimens from various depths in the Atlantic Ocean between Brtffin’s Bay aiid the Equator and found that water from the former place contained the same quantity of salts in the Burface and depth; but on passing the most southern point of Greenland ihe surface-water contained more salt than that from below the difference increasing towards the Equator. In one case he found that the more dense water occurred between too weaker portions aiid one of the series of analyses appended to this paper gives a similar result. He also observed that in some cases the amount of salt increases with the depth and in other cases it diminishes.A nnmber of specimens collected between lat. 50” 56’ and 50” 22’ N. and long. 12”6’ and 15” 59’ W. off the west coast of Ireland gave 35.613 grammes per litre of salts for the surface-water and 35.687 for a depth of from 200 to 1,750 fathoms. Before proceeding to mention the results of the analysis of deep sea water I wish to direct attention to the composition of Atlantic ooze brought up by the dredge from the eiiormous depth of 2,435 fathoms. The portion of the ooze reserved for analysis was dried in the engine-room of the “ Porcupine,” iii order to prevent decomposition ax nmch as podde ; wheii HUNTER'S ASALPSIS OF DEEP SEA WATER. 145 taken out of the dredge its colour was grey which however became nearly white on drying.Examined under the micro- scope it is found to contain a great number of extremely small shells apparently formed of carboiiate of calcium ;in addi- tion to these there are some siliceous forms. The principal constituents are carbonate of' calcium and silica. Before analyzing the ooze the chloride of sodium and other salts pre- sent from the evaporation of the sea-water were washed out. Composition of Atluntic Ooze. Depth 2,435 fitthorns ;lat. 47"38'; long. 12"08'. Silica. ....................... 23.36 Carbonate of calcium ......... 61.34 Alumina .................... 5.31 Ferric oxide.. ............... 5-91 Carbonate of magnesium ...... 4.00 99-92 The first series of aiislyses are of waters fiom the bottoni aiid intermediate depths commencing at 2,090 fathoms in the immediate neighbourhood of the station at which the ooze was brought up so that we may consider the bottom to be of the same composition in the two places.The sample from the greatest depth contains considerably more calcium than any of those succeeding which may be accounted for by the fact of the water there being in close contact with a sea bottom con-taining a large amount of carbonate of calcium while the water itself' has more carbonic acid in solution than any of the super- posed layers. All the intermediate depths contain about the same quantity of calcium. The magnesium and sulphuric acid are slightly in excess at the bottom aiid the clilorine increases towards the surface. The bromine was about the same all through; it was determined by reducing the mixed bromide and chloride of silver by means of zinc and dilute sulphuric acid and the results agree as well as can be expected from the very small quantity of salt at my disposal.The total amount is less in the bottom water at 2,090 fiathorns than in water at 1,000 fathoms namely 36.324 gramines per litre in the former and 36.473 grammes in the latter. The total amount of salts mas obtained by evaporating down a small portion of the water very carefully and slowly ; the heat was gradually increased and the vessel and conteiits weighed several times 146 HUNTER'S ANALYSIS OF DEEP SEA WATER. until the weight remained constant. It is very clifficiilt to avoid decomposing the chloride of magnesium to some extent ; but there was no other means of satisfactorily finding the total salts as I had not enough left t,o enable me to separate the potassium and sodium.The second series contain water from a much shallower part of the Atlantic. In this set we have the amount of calcium and magnesium almost constant from 862 to 100 fktlioms; the sdphuric acid is slightly in excess below and the chlorine greatest above. The salts in this case decrease from 862 to 200 fathoms-36.433 to 36.267 grammes per litre-and then in- crease at 100 to 36.619 while the 150 fathom water contains 36.701 grammes. A similar case was observed by Forcliam-mer and attributed by him to the existence of currents. The 1,270 fathoms water was from the bottom.The concluding tables show the amount of the other elements compared with chlorine taken a8 100. FIRSTSERIES. Lat. 47" 39'. Long. 11"33). ~~ Depth. 2090 36 *324 0 *8084 1*5925 3 -1002 19 '1820 0 *3114 , 1750 36 *478 0 *5337 1.3030 2.8513 19-3547 0 -4192 1500 36 -462 0 *5385 1,4394 2 *go38 19 *5659 0.3081 1250 36 *399 0 *5442 1 WXG 2 -8220 19 -3905 0 :4230 1000 36 *473 0 *5675 1-2275 2 *a971 19 -4695 0 -4302 SECOND SERIES. Lat. 49" 12'. Long. 12' 52'. Depth. Total salts. Calcium. Magnesium. su~~'i" Chlorine. Bromine. c----I1 --._I_ 862 36 *433 0.4149 1*2887 3.1906 19.3350 0 *4165 350 36 -294 0 *4285 1*3708 2 -9307 19 -2556 0 *4525 300 36 -395 0 *4560 1*3534 3 -1123 19 -1927 0 -4814 260 36,345 0 *4885 1*3210 2 -9436 19 -1827 0 *4218 200 36 -267 0 -4196 1-3534 3 *0100 19 -1939 0 -4605 150 36 -701 0 -4800 1.3470 2 -9619 19 a3844 0 *4093 100 36,618 0 *4116 1.2259 2 T384 19 *6'770 0 -3749 Lat.50" 01'. Long. 12" 26'. 1270 . 36.607 0.4720 1.3788 3.0260 19,2391 0.4742 GLADSTONE ON THE REFRACTION EQUNALENTS ETC. 147 CHLORINE= 100. Depth. Total salts. Calcium. Magnesium. Sulphuric acid. ~ ~~~ 2090 189 -3 4.181 8 -236 16 *038 188 '5 2 757 6 -732 145'28 186 -3 2 -753 7 *357 14.278 188 *2 2 *806 7 -062 14 -512 1000 187.3 2 '916 6 -304 14-880 ' 862 188 -4 2 *145 6 -659 16 *501 1270 .2 350$ 300 a 250Q 200 150m" 100 \ 1 190.1 188-5 189 -6 189 *!5 188 -9 180*6 186 *1 2 *224 2 *307 2 *546 2 -186 2 -481 2 -090 2 *453 7 -118 '7 *005 6 -995 7 *051 6 -948 6.230 7 *166 15.219 16,216 15 -345 15 *67l 15 '2'79 13 *916 15 ~727

ISSN:0368-1769    

DOI:10.1039/JS8702300144

出版商:RSC    

年代:1870

数据来源: RSC

摘要:

GLADSTONE ON THE REFRACTION EQUNALENTS ETC. 147 XVIIL-On the Refraction -Equivalents of the Aromatic Hydro-carbons and tlteii. Derivatives. By J. H. GLADSTONE, Ph.D. F.R.S. IN Professor Landol t’s important paper on Refraction Equivalents,* he shows that assuming 5 as the value of carbon 1.3 as that of hydrogen and 3 as that of oxygen we may reckon the refisaction of a large number of organic com-pounds with a close approximation to the truth. But in the table attached to an earlier paper,t there are several refraction equivalents given which are not conformable to these theoretical values. They are the equivalents of phenylic acid oil of bitter almonds salicylous acid salicylate of methyl benzoate of methyl and befizoate of ethyl. In the previous papers of Mr.Dale and myself‘,$ there had been given the specific refractive energies of a great vaiiety of organic compounds and most of these were found to be in accord- ance with Landolt’s numbers; but the following stand out cxceptioiially-phenylic and cresylic acids oil of cassia benzol toluol xylol cumol cymol carvol and eugenic acid. f Ueber den Einfluss der atomistischen Zuaammensetzung C- H- and O-haltiger fltjssiger Verbindungen auf die Fortpflanzung des Lichtes (Yogg. Ann. cxxiii 595). .F Ibid. cxxii 545. $ Phil. Tram. 1858 p. 887; and 1863,p. 317. 148 GLADSTONE ON THE REFRACTION EQUIVALENTS have since been led to assign 4.1or thereabouts as the value of nitrogen and 9.9 as that of chlorine; and these throw into the list of exceptions-pyridine picoline lutidine collidine chino- line lepidine aniline amyl-aniline nitrobenzol diiiitrobenzol chlorobenzol and trichlorobenzol.While investigating the essential oils I also found salicylate of' methyl anethol and myristicol to have remarkably high refractive indices ; and similar results have since been obtained from naphthalin benzoic acid benzoate of potassium sulpho- phenylate of potassium chloride of benzoyl sulphide of phenyl chlorhydraiiil) and thymol. The last three substances were kindly placed at my disposal by Dr. 8t e:nhous e. A glance at the names of these exceptional substances will show that they consist of the aromatic hydrocarbons with the bodies derived from or related to them ; two groups of nitro- genized bases; naphthalin; and some oxidised essential oils.In the followiiig table they are divided into these several groups:- Substance. Formula. Refraction :quivalent CalcuIated refraction tquivalent. Difference. Benzol. ................... !roluol .................... Xylol.. .................... Cumol .................... Cymol.. ................... Chlorobenzol ............... 43 *7 51 -4 59.2 66 -6 73 -9 52 *I 37 *8 45 *4 53 *o 60 *6 68 *2 46 -4 5 69 6 .O 6 *2 6 *O 5 *7 5-7 Trichlorobenzol ............. 69 *7 63.6 6 *1 Nitrobenzol ................ 56 -0 47 *6 a -4 Dinitrobenzol.. ............. 65 -2 57 '4 7.8 Aniline.. .................. Amyl-aniline .............. Sulphide of phenyl .......... Sulphophenylate of potassium. Chlorhydranil.. .............Ditto (Gladstone) ......... Cresylic acid.. .............. Benzoic acid.. .............. Phenylic acid (Landolt) .... 51 *1 91 -1 103.1 6'7 -6 85 -6 47 -7 47 *3 55 .3 56 *6 43 '2 81.2 89 '0 61 '6 78 .O 40 -7 40 *7 48 *3 48.6 7'9 9 -9 2(7 *O)6 -0 7.6 7.0 6 *6 7.0 8 $0 Benzoate of methyl.. ........ Benzoate of e thy1 (D e 1 f fs). ... Ditto (Landolt). ........... Benzoate of potassium.. ...... Hydride of benzoyl. .......... Chloride of benzoyl.. ........ Salicylous acid.. ............ Salicylate of methyl(L andol t) Ditto (Gladstone). ......... Ditto (Delffs) ............. Hydride of cinnamyl.. ....... 63.9 71 -3 71 6 62 .6 54 *6 62 -2 58 *9 68 .2 67 -3 6'7*2 75 -3 56.2 63 '8 63.8 55 .4 45 -7 54.3 48 *6 59 *1 59 .1 59 *1 58.3 7-7 7'5 7.8 7'2 8.9 7 -9 10.3 9 -i 8 -2 8 -1 17*o OF THE AROMATIU RYDROCARBONS ETC.' 4-5 45 Lutidine.. ................. C7H9N....... 56 .1 50 -8 5.3 Collidine.. ................. CdHl,N...... 65 *O 58 *4 6*6 Chinoline .................. Lepidine.. ................. C,H,N. ...... CloHgN.. .... 66 -7 80 *6 58 -2 65.8 8.6 14 *8 Naphthdin ................ CloHS........ 75 *o 60 *4 14-6 Anethol.. .................. C10H120.. .... 81 *4 68 -5 12-9 Carvol .................... UIOH140...... 76 9 7 *1 6 *8 Thymol ................... Myriaticol ................. Eugenic acid.. .............. CIOH,IO...... C10H140...... C10H1202.. ... 80 *2 76 .8 81 *1 71.1 71 -1 71 *4 9.1 5.7 9 -7 The refraction equivalents in the fourth column are calculated from the numbers given in my paper now being printed by the Royal Society viz.C = 5.0; H = 1.3; 0 = 2.9; C1 = 9.9; S = 16.0; SO = 17.0; N = 4.1; NO = 11.1. It will be seen that in every case they are amaller than the experimental numbers. The first group contains every derivative of the aromatic hydrocarbons of which the refiaction equivalent has been satis- factorily determined as far as I am aware. It will be at once seen that the hydrocarbons themselves and their chloiine sub-stitution-products are about 6.0 above what theory requires while the compounds from creosote are a little higher still. The azotised products and those containing C, are nearly if not quite 8.0 above the calculated values ; and that peculiar com-pound hydride of cinnamyl which constitutes the bulk of oil of casgia is well known to be among the most refractive and dispersive of bodies.To what can this increased refraction be attributed? It is evidently connected with the nucleus of the whole group and my first theory was that the hydrogen in benzol and its con-geners or derivatives had a higher refraction equivalent than in the generality of organic bodies; in fact that instead of 1.3 it ought to be taken at 3.5 as in hydrochloric hydrobromic and hydriodic acids or at an intermediate figure as in nitric or sulphuiic acids. Dinitrobenzol and even trichlorobenzol it is VOL. XXIII. N 150 GLADSTONE ON THE REFRAOTION EQUIFALENTS true still exhibited the increased refraction but the hydrogeii remaining unchanged was sufficient to account for an increase of 8.8 or 6.6.It became very interesting therefore to examine some member of the same group in which less than 3 atoms of hydrogen had escaped substitution. Chlorhydranil C6C1,0,H2 appeared peculiarly well adapted to the purpose especially as its 2 atoms of hydrogen are considered not to belong to the nucleus; and on examination of its solution in ether it was found to give a refraction equivalent of 7.6 that is about the usual amount above the calculated value. I am now disposed rather to regard the nucleus phenyl C6H, as an entity having an exceptionally great influence on the rays of light and to seek an analogy in that augmentation of refractive power which certain elements (for instance iron and phosphorus) undergo when they alter their atomicity ; arid this entity is not destroyed by the replacement of its hydrogen by chlorine nitric oxide oxygen or sulphur.As long indeed as this nucleus retains its integrity of constitution its special optical property continues; but when it is subjected to such chemical change as to break it up the resulting products have only the ordinary effect on light. Thus chloropicrin C(NO,)Cl, though prepared from trinitrophenylic acid C6H,(N0,),0,has only the refraction equivalent 45.2 the calculated value being 45.8. Thymol has claims even on chemical grounds to be considered a higher homologue of phenylic acid and its optical character lends much support to tliis view. It might therefore be placed in the first group. Of the other groups of substances having an exceptionally high refraction equivalent I may have something to say on a fiiture occasion.The great dispersive power of all these bodies likewise claims a further notice. In answer to a question by Mr. Perkin Dr. Gladstone stated that since the above paper was sent in to the Society he had examined the refraction of anthracene. A solution of it in beiizol gave for the hydrocarbon Cl4Hl0,the value 100-3 instead of 83.0 being an excess over theory of no less than 17.3. OF 1HE AROMATIU HYDROCARBONS ETC. He had also considered more attentively the effect which an excess of carbon in the composition of a substance exerts on its propagation of light. Among the hydrocarbons the paraffins and olefines give normal values but all the essential oils of the C1,H16 type that have been examined more than 30 in number give refi-action equivalents a little above theorj- those of the great turpentine group generally exceed the calculated number 70.8 by amounts varying from 2 to 3 those of the orange group by amounts varying from 3 to 4.The refraction equivalents of the typical hydrocarbons may be thus expressed in a series :-Hydrocarbon. Typical formula. Refraction equivalent. ____-----Paraffins .............. CnH2n +2 Normal Olefines. ............... cnH2n Terpenes .............. CnH,n -4 Aromatic hydrocarbons . . C,H, -6 Naphthalin ............ CnH,n -12 Anthracene ............ CnH2n -18 These higher numbers must be considered only as rough deter- minations but the gradual advance is sufficiently apparent.There is a similar advance in dispersion. Another illustration of the increased influence on light of carbon which is uncombined with two atoms of hydrogen or one of oxygen may be found in a series of oxidized bodiesJ which are obtained from various essential oils and differ from one another only in the quantity of hydrogen. Substance. Formula. I Refraction equivalent. ---I Peppermint camphor .. ' Cl,H2,0 Normal Bihydrate of cajeput .. C,,H,,O 7 Oil of wormwood.. .... 'lOH16' + 1 99 Carvol .............. ClOHl*O + 6 79 Anethol .............. C,OHl2O + 13 99 -.---Carbon alone in the form of diamond has only the normal refraction equivalent 5 0 TABLE OF DATANOT HITHERTO PUBLISHED.& Refractive indices. Specific Temp. Substance. Equivalents of solvent. gravity. centigrade. A. D. H. -L_.--Benzol ....................... ......................... 0-887 11 1 *4953 1 -5052 1 *5393 Ditto.. ....................... ......................... 0*878 10 1.4925 1 -5021 1 .5358 Ditto. ........................ ......................... 0*886 7 1 -4981 1.5071 1 *ti411 Cymol ....................... ......................... 0*872 11 1.4801 1 -4877 1.5130 Nitrobenzol .................. ......................... 1.193 7 1 *5438 1.5565 ...... Ditto,. ....................... ......................... 1 a191 8 1.5426 1*5564 ...... Sulphide of phenyl ............. ......................... 1.126 8 1.6244 1 -6398 1 $942 Sulphophenylateof potassium ....111 -36 of water.. ......... 1.092 11 1 *3587 1 -3638 1 *3767 Chlorhydranil .................. 23.74ofether. ........... 0-802 12 -5 ...... 1.3775 ...... Benzoic acid.. ................. 11 a14 of alcohol.. ........ 0-859 7 1.3913 1.3968 1.4116 Ditto.. ....................... 17.44of alcohol.. ........ 0‘838 8.5 1 *3806 1.3850 1 -3993 Benzoate of potassium .......... 22 -90 of water + 0 .06 K20 1-139 6 1.3917 1’3974 1.4149 Ditto.. ....................... 38.24 of water + 0 *09 KzO 1 *091 6 1 *3705 1 -3751 1 *3904 Chloride of benzoyl.. ........... ......................... 1 -228 10 1.5438 1 -5568 1 *6012 Hydride of cinnamyl.. .......... ......................... 1 *059 11 1,6045 1.6253 ...... Naphthelin .................. 7 -95 of ether.. .......... 0-789 6 1.3950 1.4005 1.4189 Anethol ...................... ......................... 0-9877 .. 1.5430 ...... 1 -6129 Thymol ...................... 18 .39 of alcohol.. ........ 0*832 8 1.3845 1 *3890 1 *4031 Myristicol .................... ......................... 0.9446 .. 1 -4848 ...... 1 -5160

ISSN:0368-1769    

DOI:10.1039/JS8702300147

出版商:RSC    

年代:1870

数据来源: RSC

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153 XIX.-Note on Bromopicrin. By THOMAS BOLASand C. E. GROVES. HAVINGoccasion to prepare a considerable quantity of bromopicrin we thought that it might be useful to state the most advant,ageous method and also a few of its properties that have been hitherto undescribed. This substance was discovered by Dr. Stenhouse in study-ing the action of bromine on picric acid,” but he found it better to prepare it in a manner similar to that employed for chloropicrin. After numerous experiments we found the following to be the best process for its preparation 4 parts of lime were slaked with 50 of water ; the mixture was transferred to a glass flask; and when it was quite cold 6 parts of bromine were gradually added with constant agitation great care being taken to prevent any rise of temperature; 1 part of picric acid was then added to the bromide of lime thus obtained the mixture transferred to a metal vessel and rapidly distilled.The whole of the bromo- picrin was coi~tained in the first fourth of the distillate and after being separated from the water was dried by chloride of calcium. The quantity obtained by the above method varied from 46.5 to 49.5 per cent. of the bromine employed the theoretical quantity according to the subjoined equation being 50.8 0 + 44Br + 19ca’’02 = 6CBr3 + 6Ca”CO + H2 NO2 13CaffBr2+ 22H20 In order to avoid loss of bromine and to obtain a pure pro- duct at one operation it was found necessary to use rather more picric acid and considerably more lime than the above equation indicates.On being subjected to analysis it gave the following results :-I. 05537 grm. substance gave 1.0442 bromide of silver. * Ann. Chem. Fharm. xcj 308. N2 BOLAS AND GROVES ON BROMOPICRIN. c ......... 12 Theory. 4.03 r. 4 Stenhouse. A 1 Br ........ 240 80.54 80.25 80.01 80.02 N .......... 14 4.69 0,.......... -32 10.74 298 100*00 Bromopicrin as is well known is liquid at ordinary tempera- tures but we find that the pure substance when cooled solidifies to a mass of prismatic crystals which melt at 10O.25 C. It is necessary that the bromine employed in its preparation should be fiee from chlorine as otherwise the product has a lower melting point probably owing to the presence of chloropicrin.Although bromopicrin as Dr. St enhous e has pointed out is rapidly decomposed when heated to its boiling point we find that under the ordinary pressure it may be distilled without change in a vacuum. Bromopicrin is not decomposed by cold sulphuric acid and is a remarkably heavy liquid having a specific gravity of 2.811 at 12O.5 C. It has also a high dispersive power and its refractive index for the line D at 20' C. is about 1.57. It is miscible in all proportions with benzol bisulphide of carbon tetrachloride of carbon chloroform light American oil ether and alcohol from the latter of which it is precipitated by water. Iodine is slightly soluble in it giving a violet-coloured solution and it also posseeses the property of dissolving indigo in small quantity. Naphthalin is exceedingly soluble in it especially when warm. Tetrabromide of Carbon. By the action of powerful bromiiiating agents on bromopicih we find that tetrabromide of carbon CBr, is produced and hope shortly to lay before the Society the details of its prepar:c t'ion and an account of its general properties. We have apparently succeeded in obtaining the same compound CBr, from carbonic disulphide and from bromoforni.

ISSN:0368-1769    

DOI:10.1039/JS8702300153

出版商:RSC    

年代:1870

数据来源: RSC

摘要:

155 XX.-On an Acid Feed-water from the Coal Field at Stellarton hTova Scotia and the Results of its Use. By Professor HOW,D.C.L. University of King's College Windsor Nova Scotia. INgiving an account of the mineral waters of this province I have mentioned* that a water with anacid reaction is reported to exist near Gair Loch in Picton county. The same county affords the strong brine originally described to the Chemical Society,t and also the subject of the present communication which is made by permission of Jesse Hoyt Esq. General Agent of' the Bcadia Coal Company at whose instance my examination was conducted. While from the nature of the circumstances under which the water is obtained to be detailed presently the results brought forward do not add to our scanty knowledge of the hypogene waters of the province except as indicating the probable origin of acid waters in coal strata they increase the number of facts recorded with regard to the chemistry of waters generally and they especially illustrate the action of impure feed-waters on boilers and the nature of the deposits and incrustations resulting from their use.For these reasons they ma,y not be unacceptable to the members of this Society as furnishing a subject for discussion. Mr. Hoyt sent me the water for analysis because he found it was having a very injurious effect upon his boilers ; he also furnished for examination the deposit and incrustation formed his object being to find a remedy for the evils observed. I speak of a water because although two waters were sent they proved to be so far of common origin that they intercommunicated and the considerable difference in their composition being rather in the quantity than the nature of their constituents probably arose chiefly from dilution by surface-water or from some other temporary cause connected with the weather.The waters were taken in December 1869 from an artificial pond and well respectively at the Acadia coal mines situated at Stellarton a name chosen recently February 1870 by the residents as distinctive for the locality from its furnishing the remarkable stellar-oil coal or stellarite a mineral substance first * Mineralogy of Nova Scotia p. 199. t At the Meeting held Peh. 16 1865. HOW ON AN ACID-FEED WATER described by myself," and at the same time compared with albertite and torbanite as distinct from coals.The pond was made to communicate with the well because the latter did not furnish enough water for the boilers. The pond rests upon the measures immediately underlying the Acadia seam of coal which is 20 feet thick and has the reputation of being remark- ably free from sulphur as are many of the coals of this field. Communication is made with the well which is sunk in the underlying sandstone by means of a tunnel driven through the same rock. With this exception there is no other member of the measures in actual contact with any of the water as the whole surface is covered with a tough red clay-drift of from five to twenty feet in thickness.The character of the water may to some extent be influenced by washings from dirt which is screened from the slack coal and piled in considerable quail- tities in the immediatevicinity of the pond and well. Hence it appears that the water is partly of surface origin. The water from the mine as pumped up is remarkably clear and is used in the neighbourhood for drinking purposes ; it does not mingle with that of the pond or well but is discharged at another point. The water from the pond was colourless and held a little yellow flocculent matter in suspension which was proved to contain hydrated peroxide of iron with a little organic matter and magnesia but no carbonates. It had no odour and no colour was given to lead paper placed in the air above the water aft8er shaking up ; its taste was chalybeate; it gave a black precipitate with sulphide of ammonium ; its reaction was decidedly acid; the gas evolved on boiling did not affect baryta-water.The following were the results of quantitative analysis of the filtered water made soon after collection. The nomenclature used in my report as more generally intelligible to practical men than any of the latest proposed is retained :-* Edin. N. P. Journal and Silliman's Journal 1860. FROM THE COAL FIELD AT STELLARTON ETC. 157 Contents of Pond Water in the Imperiul Gallon. Grains in 70,000. Sulphate of lime ................... 8-81 Sulphate of magnesia ................ 5.91 Sulphate of protoxide of iron.. ........4-96 Sulphate of potash .................. 1-53 Chloride of sodium .................. 0.28 Chloride of potassium ................ 0.67 Silica .............................. 0.25 Ammonia ......................... traces Organic matter ...................... small Free sulpliuric acid (oil of vitriol) ...... 1-92 24.33 Specific gravity at 57" Fahr. ...... 1000*299 The water increased mnch in acidity when boiled down; after about four-fifths had boiled away the amount of deposit was equal to about half a grain to the gallon; the residue on evaporation heated in a porcelain dish became black. The sul-phuric acid of the sulphates and the comparatively large imount of iron may have come chiefly from pyrites in the "djacent coal-dirt and the fi*ee sulphuric acid from the subse-pent alteration of protosulphate of iron.The well-water the actual feed-water of the boilers was very turbid and was constantly depositing a yellow substance mnsisting of hydrated peroxide of iron organic matter and ,uagnesia. Its reaction was distinctly but not strongly acid ; it had a strong chalybeate taste and gave a black precipitate with sulphide of ammonium; it had no odour gave more gas than that from the pond on boiling and the gas in this case also was not carbonic acid. The results of the analyses of the filtered water soon after its collectiou were the following :- 158 HOW ON AN ACID FEED-WATE‘k Contents of Well WLter in the Iinperial Gallon. Grains in 70,000. Sulphate of lime ....................25-69 Sulphate of magnesia. ............... 9.45 Sulphate of protoxide of iron ........ 4-58 Sulphate of potash.. ................ 6-44 Chloride of sodium.. ................ 0.40 Chloride of potassium.. .............. 0.88 Silica.. ............................ 0.52 Organic matter .................... very small Free sulphuric acid (oil of vitriol) ..,. 0.43 48.39 Specific gravity at 57” Fahr. ...... 1000*891 This water deposited the whole of its iron along with some magnesia and no doubt organic matter on boiling down ; when at about one-fifth of the original bulk its total deposit amounted to four grains for the gallon; this deposit contained 120 carbonates. The difference in composition between this water and the preceding may have arisen from their inter- communication being temporarily broken by a hard frost which occurred early in December and the dilution of the pond water during the subsequent “soft spell” in which the waters were collected.The sandstone of the tunnel and well would produce little change. It is evident that a good deal of iron has been removed doubtless by organic matter. The fiee sulphuric acid has probably been partly neutralized by carbonate of lime existing in the well water itself. At my request Mr. Hoyt tested the waters in the pond the well and the boilers with litmus paper and in each case found an acid reaction which I considered on observing the resulting tints of the papers returned to me to be about equal to that I had obtained in the bottled waters as received and as evaporated.The deposit or sediment formed in the boilers was of a bright red colour in dry and soft cakes up to an inch or so in thick- ness apparently uniform in quality. Heated in a tube it gave water with vapours smelling strongly of acrolein arising from the presence of grease introduced of course from the FROM THE COAL FIELD AT STELLARTON ETC. 159 machinery. It contained 110 carbonates and only the merest trace of magnesia; a few minute black specks were observed on solution in acid Analysis gave :- Water and greasy organic matter . . . . . . 9-11 Peroxide of iron and a little alumina . . . 54.34 Anhydrous sulphate of lime . . . . . . . . . . . . 36-55 The incrustation formed on the boilers was described as so compact as to be removed ~vitli much difficulty.As I received it the most solid portions were in cakes nearly a quarter of an inch thick in parts white and red inside as from a mixture of peroxide of iron and sulphate of lime ; some organic matter was also present. As a whole the incrustation was a dry mass of the colour of Turkey umber ; it contained twigs and fibres of roots. Heated in a tube it gave a good deal of water and oily white fumes containing acrolein ; carbonates were absent and a mere trace of magnesia was found with also a few minute black specks remaining as above on solution. The analytical results on selected hard portions were :-Water and greasy organic matter . . . . . 14-43 Peroxide ofiron and a little alumina .. . . 13.30 Sulphate of lime (anliydroiis) . . . . . . . . 72-27 It is not surprising that with such water as has been de- wribed the boilers should be much injured and that so large a quantity of iron should be found in the deposit a quantity which indeed may be called enormous when we find Dr. Phipson quoted as instancing a red deposit containing more than 9 per cent. of peroxide of iron as the result of the action of an impure water such as those contaminated with metallic salts and other kinds of refuse from chemical works and especially liable to induce corrosion." In addition to the simply chemical action of the sulphuric acid originally free and that liberated by the concentration of the Stellarton water which would of course attack even homo- geneous iron and whose influence would be largely increased * Phi pson on Boiler Dposits reviPwPd in Chemical Newa xvi 131.HOW ON AN ACID FEED-WATER ETC. by the electrical relations of the different portions of the boiler plates consisting no doubt of the electrically non-homoge- neous portions found as pointed out by Mr. Mallet in mought-iron and blister steel there would be similar if less injurious results from the action of the alkaline salts classed by Professor Chandler" as electrically corroding agents. If ang brass or copper should be in contact with the metal the electrical action on the iron would of course be intensified. The oxide of iron is derived partly from the water itself; but principally no doubt as a good deal must be deposited in the well from the decouiposition of the iron salts resulting from the action OP the boiler plates.Both in the deposit and incrustation minutc black specks were said to be present ; these were not given in the quantitative results as being too small in amount. They effervesced with nitric and with hydrochloric acid but remained black 60 that they no doubt contained iron a.nd graphitic carbon; and they may have been mechanically detached froni the boiler with the incrustation or have resulted from its occa- sional local burning into seales or from the local corrosion detailed by Mr. Paget in his interesting paper read before the Society of Arts and given in abstract in ths '' Chemical News," xi 219 230 in which he dwells at some length on the electrical relations to which I have only alluded. it Report on Water for Locomotives and Boiler Incrustations New York 1865.

ISSN:0368-1769    

DOI:10.1039/JS8702300155

出版商:RSC    

年代:1870

数据来源: RSC