摘要:

THE ANALYST. MAY, 1898. PROCEEDINGS OF THE SOCIETY OF PUBLIC ANALYSTS. JAPANESE WOOD- OIL. BY J. H. B. JENKINS, (Rend at the Meeting, March 16, 1898.) JAPANESE wood-oil (Chinese wood-oil, Tung-oil) is still so little known generally, that the results of the examination of a sample which recently came into the author's hands may be of interest. I t is an oil of considerable viscosity, high density, and remarkable drying properties, and is produced from the nuts of the wood-oil tree (Aleurites Cordatn) in Japan and China, where it is used in large quantities in paint- ing and calking, and for many other industrial purposes. I t is said to be extensively used in native medical remedies in virtue of its purgative, emetic, and very poisonous properties when freshly prepared. For comparison with the results obtained from this sample, others are collated from an earlier sample examined by the author a year ago.Most of these latter results have already appeared in the Jozw. Soc. Chem. Iizd., 1897, 193 and 195." The following other references to work done on the oil may be useful : Cloez (Bull. Soc. Chim., xxvi., 286, and xxviii., 23) ; Davies and Holmes (Phn7.. Jour., 1885, 634 and 636); Deering (Imp, Inst. J o u ~ . , August, 1896, p, 303) ; De Negri and Sburlati (Sc. Mom, September, 1897, p. 680). Present sample. Specific gravity at 60" F. ... ... 0.9343 Glycerin ... ... ... ... 10.6% Viscosity at 60" F. (water takes 28 sees.) ... Solidifying point ... ... ... below - 17" C. Bromo-thermal rise ( = x") ... ... 21.4" C. Calc. iodine value (2' x 7.0) ...... 149.8 Insoluble fatty acids ... ... ... 96.0% Unsaponifiable matter . . . ... ... 0.63% Free fatty acids (calc. as oleic) . . . . . . 1.83% 858 sees. Calc. iodine value (zo x 5.7) ... ... 122.0 Earlier sample. 0.9385 0.44% 3.84% 96.4% 10.4% 1433 sees. below - 17" C. 23.4" C. 133.4 163.8 * I n the ANALYST for February, 1898, p. 43, there is a n abstract relating to Japanese wood-oil taken With the exception of a couple of interpolations aiid errors, the particulars are from German periodicals. derived wholly from the author's paper in the Jour. Soe. Chem. Incl. above referred to.-J. 11. B. J.I14 THE ANALYST. Iodine value (Hiibl) ... ... Saponification value (Rfgms. KHO) Specific temperature reaction . . . The insoluble f u t t y acids gave : Melting point ...... ... Bromo-thermal rise ( = z") ... Calc. iodine value (x" x 5.7) Calc. iodine value (x" x 7.0) Iodine value (Hiibl) . . . ... ... ... Present sample. ... 149.7 ... 192 ... 298 ... 30-31" C. , . . 21.0" c. ... 119.7 ... 147.0 ... 144.1 Earlier sample. lG5.7 194 330 37" c. 126.0 154.7 150 -1 22.1" c. Viscosity.-The viscosity was taken with Redwood's instrument, through which the same quantity of water (50 c.c.) flows in 28 secs., and averages pure rape-oil in 470 secs., at 60" F. Spccijc Temperature Recution (Mauinen6 Test). -The peculiar property of the oil of solidifying in contact with sulphuric acid makes it necessary to largely dilute it before this test is applied. When the acid is added to a solution of 10 grammes of Japanese wood-oil in 40 grammes of diluent, it becomes for a time semi-solid, but soon thins again and perinits the maximum temperature to be recorded.A thin mineral oil was first tried as diluent, and an allowance made for the fraction of heat due to it. Mineral oils, however, heat very slowly as compared with fatty oils on treatment with the acid, and such a correction was open to suspicion. For this reason olive-oil was adopted instead, and, although the correction-figure was larger, it was thought to be inore satisfactofy. The figures given above are calculated from experiments made on 10 gramrnes of sample diluted with 40 grainmes of olive-oil. Valenta's Test.-The temperature of turbidity with glacial acetic acid was 44" C. The earlier sample gave 47" C. ElnZ'diiz Test.-In this test the oil darkened considerably.Examined after twenty-four hours, there was an oily upper layer on a more solid portion on the bottom ; when stirred up the whole would slowly flow. Becchi's A?*gentic Nitrate Test.-A quarter hour's heating with the reagents pro- duced no appreciable deepening of colour. This is different from the earlier sample, which gave a deep reddish-brown coloration. Hcclphm's Test (Reme de Chiin. Ind., February, 1898).-In this test the presence of cotton-seed oil is indicated by the production of a red coloration on heating the suspected oil with amyl alcohol and CS, containing some dissolved sulphur. Each of the samples of Japanese wood-oil when tested thus gave negative results. The fact that one of the samples gave the Becchi reaction strongly, but no coloration with the Halphen test, is interesting.Oxidizing aizd Dryiizg Properties.-Four grainmes of the oil were exposed in the boiling-water oven in a, shallow porcelain dish 7 em. diameter, and weighed after successive hour's exposures. At first there was a slight loss, probably due to moisture in the oil ; the average gain of weight during the first eight hours' exposure was 0.26 per cent. per hour. I n six hours the surface was entirely covered with a, crinkled skin. The earlier sample, under these conditions, gained during four hours exposure at the average rate of 0-36 per cent. per hour, and was covered with a, crinkled skin in two hours. A sample of linseed-oil similarly exposed had no sign ofTHE ANALYST. 115 any skin on the surface at the end of eight hours, and the average gain per hour was 0.10 per cent.Opticctl Proiierties.-The sample did not cause any rotation of polarized light. I t had very high refractive power at 19" C, ; and with the sodium light, its refractive index was 1.503. The apparatus used (vide sketch) was a small flask into the neck of which a glass tube was ground. The tapering lower end of this tube reached below the surface of some mercury at the bottom of the flask. The rest of the flask was completely filled with the oil. During the expansion of the oil a little of the mercury is forced up the central glass tube, but air is rigidly excluded from the oil during its exposure to the heat. The flask was heated in a glass air- bath. The oil was in this way heated first for two hours at 200" C.but remained liquid, then the temperature was raised to 250" C, and kept at that for another couple of hours, during which time the oil thickened and the minute bubbles of gas, which had been arising through the oil for some time, were now held entrapped en route. When cold, the oil was found to have been converted into a sticky elastic jelly. The earlier sample of Japanese wood-oil, when similarly treated, yielded a hard, dry, elastic solid. There was no darkening of colour in either case and the products remained clear. There was a decrease of solubility of the oil in all ordinary oil-solvents in proportion as this polymerization change had taken place. This peculiar property was noticed by Cloez, who also found that exposure to direct sunlight, without any heating, was suficient to solidify the oil in a few days.Possibly the great difference in viscosity which is noticed in the two samples may be due in some degree to a partial polymerization of one of the samples. Action of Bronzi?ze and Iodi?ze.-The iodine value of the oil was determined by the Hub1 method, and the bromo-thermal test applied in the way laid down by Hehner and Mitchell (ANALYST, July, 1895). A year ago these two tests were used comparatively by the author in the examination of a variety of fatty oils, including Japanese wood-oil. I t was then found that the remarkable constancy of ratio between the temperature rise on bromine treatment and the iodine value which exists for fatty oils, did not extend to the Japanese wood-oil.Thus, whilst the factor 5.7 applied to the thermal rise gave the iodine value for all the other fatty oils examined (excluding '' blown " oils), the factor 7.0 had to be applied for the Japanese wood-oil. I t is found that this peculiarity exists also with the present sample of the oil, as well as with the fatty acids from each. (By an error of calculation, it has been stated, Jour. SOC. Chem. Ind., 1897, 193, that this anomaly disappears when the fatty acids are examined ; this, however, is not so.) The fact that the heating on bromine treatment is not so great as one would expect from the iodine value suggests that the action of the bromine on the oil is not so extensive as that of the Hiibl reagent; but this is hardly SO, as the bromine absorptioiz value of the oil is not low as compared PoZyinerixcttion on Heating.-The oil was heated out of contact with air.116 THE ANALYST.with the iodine value. The cause will probably be found in a peculiarity of chemical structure of the fatty acids. I n trying to get some light on the anomaly, the author tried the effect of a chloroformic solution of iodine on the oil. A couple of grammes of the oil were dis- solved in 5 c . ~ . of chloroform, and 5 c . ~ . of a saturated solution of iodine in chloroform were added with agitation, when the whole was rapidly converted in a jelly, the stiffness of which was proportional to the amount of oil taken. The amount of iodine in the 5 C.C. of chloroform is quite inadequate to saturate the oil. I n the earlier sample of Japanese wood-oil 1 gramme of the oil was sufficient to produce a jelly in a couple of minutes, but the present sample is not so sensitive; 2 grammes of it produce a jelly in a couple of hours, and a solution of 4 grammes instantly jellifies on treatment.This peculiarity has not been noticed with any other fatty oil. A solution of iodine in other solvents produces the same effect. If a saturated solution of iodine in CHCl, or CS, be dropped upon the oil, it immediately solidifies it. Bromine, whether in solution or otherwise, has no similar action on the oil. The melting-point of the fatty acids from the later sample was not very definite. The solidified fatty acids have a peculiar wavy or rosette-like appearance. The author is indebted to Messrs. Horner and Sons, of Mitre Square, Aldgate, for the later sample.DISCUSSION. The President having invited discussion : Mr, HEHNER said that, owing to the courtesy of Mr. Jenkins, he had been able to make some experiments on a small sample of this oil. He had independently found the remarkable gelatinization referred to, which was a most characteristic property of this oil, This oil was quite different in constitution from any ordinary oil which gave figures of this kind. From the high iodine number it was quite plain that the oil must contain a highly unsaturated acid, in this respecb approaching linseed-oil. Linseed-oil formed a hexabromide which was exceedingly insoluble, a proof that linolenic acid was present, and one would expect that this Japanese wood-oil, from its high iodine number, also contained a considerable quantity of linolenic acid. But absolutely no insoluble hexabrvmide was formed, showing that it must contain a different unsaturated acid from any of those known at the present time. The figures for rise of temperature in the bromine absorption test really applied only to ordinary oils, and he hardly considered this an ordinary oil as hitherto known to chemists. The factor, therefore, failed; but it failed also in every other unsaturated compound in which the acid was other than oleic, linolic, or linolenic acid. This was another proof that Japanese wood-oil contained an acid which was not one of the generally known unsaturated acids.

ISSN:0003-2654    

DOI:10.1039/AN8982300113

出版商:RSC    

年代:1898

数据来源: RSC

摘要:

THE ANALYST. 117 A TYPICAL NORTH-EAST LANCASHIRE RIVER. BY 3’. R. ~’SHAUGHNESSY. (Read at the IVeetiizg, March 16, 1898.) SOME time ago I had occasion to examine the water of the river Calder, a stream which flows through Rurnley. The results of the analyses themselves are only what one would expect to find in a polluted water; but when the series is considered collectively, and in conjunction with the nature of the pollution taking place at different points along the stream, a few interesting points present themselves. Acting on the suggestion of our President at the last meeting, I thought that these points might not prove uninteresting to the members of the Society. The stream rises on a moor, and the condition of the water here probably coincides with that of the Padiham drinking-water, the analysis of which is contained in sample No.1 of the table. I t flows for some distance through the open country, and then passes through the town of Colne. There there are a number of cotton factories, skin-dressing establishments, etc., and just below the town is the sewage- farm. About half a mile further on the Pendle water, which nearly equals the main stream in bulk, enters. Two miles farther on the stream passes the sewage-farms of Nelson and Brierfield. Lower down still on the bank Burnley sewage-farm lies, and a branch of the river which flows through Burnley enters. A couple of miles more and the stream runs through Padiharn, a small town of about 15,000 inhabitants. I n the centre of Padiham a brook enters, which consists largely of the refuse from a print-works and a large chemical works.Below Padiham another smaller brook enters similar to the last. A mile or so lower down there are two sewage-farms and a paper-mill, with some settling-tanks for purifying the refuse. The river then flows on through open fields, and receives the effluent from still another sewage-farm through the medium of one tributary, and the refuse from a print-works through a second tributary. I n the table of analyses the Padiham drinking-water, which appears under No. 1, was analysed in order to give an idea of what a typical good water of the district was like. Sample No. 2 was taken at a point on the moors about a mile or so from the source of the branch of the river selected. There the dark colour is due to peaty matter, the “total solids’’ are low, and the “loss on ignition” what one would expect in a peaty water.suspended matter ” is very low, as is also its loss on ignition, showing that it probably is all derived from the bed of the stream. The lime, chlorine, and sulphuric acid are low, whilst the “ oxygen absorption” and ‘( free ” and “ albuminoid ammonias ” are fairly high. Sample No. 3 was taken below the first large town, viz., Colne, and gets the benefit of the effluents from two sewage-farms. There is a general.rise in all the constituents, especially in the free and albuminoid ammonias. We note, however, a fall in the oxygen absorption, and, curiously enough, this corresponds with the trace of nitric acid found in this sample, which shows that oxidation must have taken place, Finally it disgorges itself in the Ribble at Thacking Hall.The118 THE ANALYST. Sample No. 4 was taken at a point below the towns of Nelson and Brierfield, and the river above this point receives the effluents from their respective sewage- works as well as the two previously mentioned. There we note the immense rise in free ammonia, whilst the albuminoid ammonia falls slightly and the chlorine considerably. This latter fact is due to the entrance of the Pendle water, which is in fairly good condition. Sample No. 5 was taken below Burnley sewage-farm, and the point where the branch of the stream which flows through Burnley enters. Here the oxygen absorp- tion and free and albuminoid ammonia reach a terrible altitude. I n the first four samples we note that the ratio between the loss on ignition of the total solids to the total solids is, roughly, about one-third.But in sample No. 5 this ratio falls considerably. This is in all probability due to pollution from manufacturing sources in the town of Burnley. Between the points where samples No. 5 and No. 6 were taken there are no sewage-farms. At the same time, there is a considerable amount of water entering the river from brooks and small streams, and the diluting effect of this water is seen in the immense fall in free ammonia. On the other hand, these brooks, etc., consist largely of refuse from print works and chemical works, and their effect is seen in the rise in chlorine and sulphuric and total solids. The whole of the samples from No.2 to No. 6 were taken in succession on the same day. Sample No. 7 was not taken till the morning following, and hence is not strictly comparable with the other samples. Between the points where No. 6 and No. 7 were taken there are two sewage-farms and a paper-mill. We see that every- thing has fallen off but the free ammonia and sulphuric acid. The rise in the former is undoubtedly due to the effluents from the sewage-works. The latter is probably due in part to manufacturing sources, pollution from which, I have reason €or believing, takes place pretty heavily during the night. If we examine the ratio between the loss on ignition of the suspended matter and the suspended matter itself, the steady rise in this ratio as we descend the stream is very striking. As an appended note to this paper, I would like to draw attention to the use of salicylic acid as a means of preserving a standard solution of sodium thiosulphate, a solution which is much used in water analysis.The figures in Tables I. and 11. were obtained by Messrs. Richmond, Boseley and myself in our ordinary routine work by titrating the thiosulphate against 10 C.C. of standard permanganate. 11. I Before addition of salicylic acid : 13 vii. ... 14.6 C.C. ... 22 vii, ... 14.5 C.C. ... 9 days ~ 22 viii. .. 15.75 C.C. ... 40 ,, ~ 7 ix. ... 20.20 C.C. ... 55 ,, 9 ix. ... 21.00 C.C. ... 58 ,, ~ 11 ix. ... 23.65 C.C. ... 60 ,, I 22 ix. ... 49.00 C.C. ... 73 ,, , I I. After addition of sulicylic acid : 25 ix. 97 ... 13.95 C.C. . .. 27 ix. 97 ... 13-95 C.C. ... 29 ix.97 ... 14-15 C.C. ... 2 x. 97 ... 13.95 C.C. ... 2 x. 97 ... 13.90 C.C. ... 11 x. 97 ... 13.95 C.C. ... 25 x. 97 ... 13.80 C.C. ... 28 x. 97 ... 13-90 C.C. . . . 28 ii. 98 ... 13-90 C.C. ... 2 days 4 $ 9 7 3 , 7 9 , 16 9 , 30 , 9 33 $ 7 156 ,,THE ANALYST. 119 No. of Sample. Colour . . . ... Smell ... ... Total solids . . . Loss on ignition Suspended matter Loss on ignition Lime (CaO) . . . Chlorine ... Sulphuric acid Nitric acid (N,O,) Oxygen absorbed Free ammonia ... Albuminoid am- monia ... (SO,) ... ... A TYPICAL RIVER. Results stated in parts per 100,000, 1. Almost none Earthy 9.10 3.00 - - 1 -04 1.00 0.89 None 0.098 0 a006 0-006 2. Dark yellow Faintly earthy 14.30 4-30 0.81 0.06 3 *72 1.20 1.39 None 0,333 0.030 0,015 3. Faint yellow Foul 31.40 8.90 1.34 0.97 4.88 3.40 3.56 0.50 0.322 0.163 0.026 4. Yellow Foul 32.20 11.20 2-89 1 -78 4.68 2.30 3 -95 None 0-377 0.472 0.022 5 . Yellow Foul 32.10 7-50 2.34 1-79 4.82 2 *70 4.67 None 0 414 0.784 0-040 6. Yellow Foul 36.80 10.40 1.93 1.52 5.60 4-40 6.03 None 0.496 0,404 0.044 7. Yellow Foul 35.00 9.50 1.39 1.03 5 .OO 3.50 6.71 None 0-381 0.462 0.041

ISSN:0003-2654    

DOI:10.1039/AN8982300117

出版商:RSC    

年代:1898

数据来源: RSC

摘要:

THE ANALYST. 119 A NEW FORM O F CONDENSER. BY CECIL H. CRIBB, B.Sc., F.I.C. (Read at the Meeting, March 16, 1898.) The form of condenser with which Liebig’s name is inseparably connected has served its purpose so well and has been in use for so long that it seems almost sacrilege to attack such a venerable institution. There can be no doubt, however, that theoretically it is most inefficient in proportion to its size, and that practically, in addition to being very cumbrous and heavy, it is in many other ways extremely inconvenient. A number of other forms have from time to time been introduced, but up to the present not one of them has been at all largely adopted. With regard to the eficiency of the Liebig condenser, the chemist whose laboratory operations are generally conducted on a small scale has but little reason to trouble.Provided condensation be complete, the actual amount of cooling water used is of little importance, but the absurd size of the present apparatus is a matter much more worthy of consideration. The great amount of bench-room taken up by condensers, and the expense involved in laying on water over large areas, renders it desirable that the space given up to distillation purposes should be as small as is conveniently possible. Any reduction in the size of the condensers must, to he of service, be acccmpanied by a corresponding increase in efficiency. A theoretically perfect condenser should present to the vapour a cooled surface as large as possible, while the space into which the vapour has to pass should be as120 THE ANALYST.small as possible consistent with its offering only a, very low resistance to the passage of vapour into it. I n any case, whatever its absolute or relative size may be, it should be of such form and dispcxsition that the stream of incoming vapour can drive the air before it, so that the major part of the condensing space is filled with the pure vapour. The Liebig condenser is obviously far from fulfilling these conditions ; the worm condenser has nearly all the bad points of the Liebig, of which it is really only a coiled form. The spherical condensers also, now becoming so popular on account of their smallness, are as a rule made with the condensing chamber much too large. The general plan of the form now exhibited is shown in the accompanying - = F I F I G .1. sketches. The vapour enters through the tube A into the condensing space B between the two tubes, C and D ; after condensation the distillate passes out through E. The cooling water passes down the tube F into the interior of C, which it fills, and, running over the rim at the top, passes in a thin stream down the outside of D, finally flowing away through the escape pipe G. When used as a reflux condenser, the vapour, of course, passes up through E. After allowing the liquid to get into full ebullition, so that the air is driven out of ths condensing space, the niouth of A may be completply closed with a cork, thus avoiding even the possibility of loss with volatile liquids such as ether. The apparatus must obviously always be used in one and the same position, ie., with its axis ver- tical.This is a distinct advantage, because it is very easily so supported, and because, when thus disposed, it takes up a minimuin of space on the bench. An absolutely vertical position, however, is not necessary. I t is preferable that the top of the condenser should slope, if at all, towards the flask or retort from which the liquid is being distilled. To obtain the greatwt possible efficiency in working, special steps should be taken to ensure the even distribution of the water over the outside of the condenser, as the adhesion between the water and the glass or metal, and the surface tension of the water itself, are reduced to a minimum at high temperatures, so that the cooling water tends to run in narrow streams outside D, instead of spreading out.This is easily remedied by covering D externally, either partially or entirely, with some absorbent material, such as blotting-paper or linen (the latter as a permanence is to be preferred). I n addition to this a cork I (Fig. l), with a number of vertical grooves cut round its outside, is inserted into the mouth of C. The cork is perforated for the cold-water supply tube F, and the water leaves the interior of C by the grooves in the cork, thus gett'ing well distributed round the outside of -the condenser. This little device hasTHE ANALYST. 121 the further advantage of preventing any water getting spilt if the condenser receives a sudden knock or jerk whilst in action. With metal condensers the cork may be replaced bya metal disc H (Fig.2) attached to the cold- water supply tube, and arranged so as to leave space either below it (as in the sketch), or outside it for the water to flow out of the cup on to the exterior of D. To ensure the utilization of the whole available cooling surface, a wire or band of metal K (Fig. 2) may be coiled spirally round the interior of the condensing space, thus converting it into a flat spiral channel.+ E@ciency.--This may be treated both from a theoreti- cal and from a practical standpoint. Theoretically it is obvious that the new form has many D- points of superiority over the Liebig, the worm, or even the spherical condenser as at present made. The condensing space in the small metal condenser exhibited, of which the outside dimensions of the body are The glass one shown - measuring outside 1% x 53 inches-has an internal capacity of 30 c.c., while a Liebig's condenser, of which the water-cooled part measured 19 x $', was found to hold 55 c.c., and a ball condenser 3+ inches in diameter was found to contain over a hundred cubic centimetres.That the practical performance of the condenser is a t least equal to its theoretical promise may be seen from inch x 44 inch, is only 9 cubic centimetres. the following figures :- F I G . 2. Small Metal Condenser. Glass Condenser. (1). (2). (3). (4 ). (.5). 65' C. 76" C. 61" C. 47.5" C. Temperature of effluent } 520 c. cooling water . . . ... ... J 60" C. 61" C. 41" C. 35.5" C. Ternperahre of distil- i 480 c. C.C. of cooling water . . . G.c. of distillate per 2,642 late ...used per hour hour . . . ... ... 1- } 40,000 40,000 7,200 6020 2093 4,128 1,017 7 65 355 1 1 1 1 1 __ . _- 1 -_ Ratio of quantity of dis- tillate to that of cool- ___- ing water . . . ... \ 15:14 9.69 7.8 7.87 5.9 The resistance of the metal condenser, working as in colunin (a), was roughly equal to one inch of mercury, the volume of the steam condensed in one second being two hundred times the actual capacity of the condenser. When the water supply was stopped, the resistance rose to 1: inches of mercury, One of the metal condensers with a body measuring 49 x 1; outside, but with an iinnecessarily large condensing space, when connected up $0 a high-pressure boiler ii For all ordinary purposes this is quite unnecessary.122 THE ANALYST.(working at 43 lbs. pressure), yielded 8,040 C.C. of distillate per hour. It was, however, working under somewhat disadvantageous circumstances, as it was found inipossible to fix it except in a somewhat slanting position, so that the water ran mainly down one side of the exterior. The glass condensers have not yet been tested as to their extreme capacity, but they have been found ample for any and all of the ordinary laboratory operations, in which 500 C.C. per hour may be taken as the maximum rate of distillation. The metal forms can be used with a ratio of distillate to cooling water as high as & without any steam escaping, though the distillate itself is nearly boiling. I n addition to its great efficiency and extremely small size and weight, the new form of condenser has the following advantages :- It is always used in one and the same position, i e ., vertical, in which it takes up a minimum of bench room, and in which also it is very easily fixed, a little bracket projecting from the wall, or a hole in a block sliding up and down a retort stand being ample for the purpose. If greater rigidity is required, the upper end may also be held by a wire or spring clamp attached to the top of the tube F. I t can be made, if necessary, in both metal and glass, so that the inner tube C can be withdrawn from the outer. The whole of the interior of the condensing space is thus at once open to view, and can be wiped dry and clean with a duster. To effect this in the metal condensers a slip-in or a screw joint is made at J (Fig.2 ) ; in glass condensers the fused joint at J (Fig. 1) is replaced by an india- rubber joint. Owing to the cooling water running down 0~6tside the condenser, it is practically impossible for the escape tube to get choked up with fur, as happens some- times to a Liebig's condenser after long-continued use. The escape tube G should be made about twice the diameter of the cold-water delivery tube as a further safeguard. Owing to the vertical position and to the small diameter of the extremity, the condenser is very easily connected in an air-tight manner to a receiver, so that, with the addition of a little side tube at L for attachment to a pump, distillation may be conducted under reduced pressures. Or, if a suitable mercury valve be attached to L, and a little air be sucked out at the commencement of the operation, distillation or digestion may be carried on in an entirely closed space. In tropical climates, or with liquids of exceptionally low boiling-point, the tube Cl may be filled with ice, and the water allowed to flow up through it. The very thin layer into which the water is spread when pouring down the outside of the condenser greatly facilitates evaporation, so that the latent heat of vaporization, which has mainly to be derived from the vapour undergoing condensa- tion, effects a great saving in the cooling water used. This is especially the case with liquids boiling above 100" C., but may be easily shown in the case of water by cutting down the supply of cooling water to a niinimuin, when the water at the top of C is sometimes as much as 10" hotter than that issuing from G. Finally, its simplicity renders it easy of construction in almost any material likely to be employed. The condensers can be obtained from Messrs. J. J. Griffin and Sons, Garrick Street, and from Messrs. C.. E. Miiller and Co., High Holbom.

ISSN:0003-2654    

DOI:10.1039/AN8982300119

出版商:RSC    

年代:1898

数据来源: RSC

摘要:

THE ANALYST. 123 THE ANALYSIS OF MARMALADE. BY L. K. BOSELEY, Chemist to Messrs. T. Keiller and Son, Limited. (Read at the Meeting, March 16, 1898.) HAVING had occasion lately to work out some methods for the analysis of marmalade and jams, I have thought that a description of these, together with several results showing the composition of marmalade, might be of interest to the members of this Society . Very few analyses on this subject have been published up to the present time- indeed, a few made by Mr. Carter Bell, the Analyst for Chester, are the only ones I know of. These analyses, which have been published quite recently, are not at all in agreement with any which I have myself made; among them are four analyses of marmalade, of which I give particulars, together with a few quotations from the report : ‘( I n the manufacture of jam on a large scale glucose, or inverted sugar, is often used in the place of cane.But to attempt to estimate this adulteration would be hopeless, for in the manufacture of jam the acids of the fruit convert the cane- sugar, more or less, into glucose.” The following analyses are then given : Water. Glucose. Cane-sugar. Ash. 1. Marmalade ,.. 20.5 21.05 37.77 0.305 2. ?, ... 21.8 15.62 34-38 0.31 3. 9 , ... 22.5 24.39 25.61 0.30 4. 2 9 ... 19.5 21-73 14-63 0.26 From the remarks quoted above, it would seem that Nr. Carter Bell is unable t o distinguish between the product of the action of sulphuric acid on starch, usually known as glucose, and the product of the action of a fruit acid on cane or beet sugar, usually known as invert sugar.The sugar estimated in these analyses appears to me to be very much too low ; for if the last sample be taken, and the water, glucose, and cane-sugar added together, they amount to 55.86 per cent., a, figure which leaves 44.14 per cent. of dry fruit (the water being estimated), which is not possible. My own experience goes to prove that marmalades from various sources contain from 2& to 58 per cent. of dried fruit. The probability is that both the figures for water and for sugar are much too low, as I never met with a marmalade with so low a water as 19.5 per cent., and one which containsd 36.36 per cent. of total sugar, more than half of which was glucose, would be little thicker than water. The following are the methods in use in my laboratory : Water.-This is estimated by taking a flat-bottomed porcelain basin containing a glass rod, and weighing into it about 7 to 8 gramines of the well-mixed marmalade.This is warmed, and dissolved in a few C.C. of 40 per cent. alcohol. From 12 to 15 grammes of silver-sand, which has been previously dried, if necessary, are now weighed into the basin, and the marmalade, sand, and alcohol thoroughly mixed with the glass rod. The basin is then heated on the water-bath for an hour, when 5 C.C. of absolute alcohol are added, and the basin again heated for one hour ; after this it is124 THE ANALYST. transferred to the air-bath and dried at 95-100" C. for thirty-six hours, or until the weight is nearly constant. Acidity.-This is estimated by weighing out 20 grammes of the marmalade, titrating with Fa soda, with phenolphthalein, or litmus-paper as indicator.The number of cubic centimetres used, multiplied by 0.035, gives the percentage calculated as citric acid. SzLgurs.-The following methods are the best, supposing only cane and invert sugar to be present : Weigh out 65.12 grammes of the well-mixed marmalade in a sknall beaker, add successive quantities of coZd water-say, 50 c.c.-stir well, and decant into a 250 C.C. flask. Then transfer the peel to the flask, add basic lead acetate, until the solution is only slightly acid, make up to 250 c.c., and mix well. It is best not to add sufficient basic lead acetate to neutralize the solution, as one is apt to get lead in the filtrate, this being an objectionable feature, as a slight pre- cipitate is produced on adding acid to invert the solution which is apt to interfere with the polarimeter reading.The contents of the 250 C.C. flask are now filtered through a dry filter, and polarized at t" C. Fifty C.C. of the filtrate are placed in a flask, and 5 C.C. of pure, strong HC1 added, and the flask is heated on the water-bath till a thermometer suspended in the middle of the flask indicates 68" C. in ten minutes. Cool quickly to to, and again polarize. Then, Cane-sugar = Direct - -inverted reading (this is the well-known Clerget formula). t o 144 -- 2 (Cane-sugar - direct reading) 100 Invert sugar = ____---I_. l_l t" 44 -- 2 _ _ _ ~ , If glucose be present it will be indicated by the inverted reading being + instead of - , or, at all events, being very much smaller than usual.If this he the case, it will be necessary also to determine the cupric reducing power (in duplicate). The details of the method are as follows : Weigh out 13.024 grammes of pure cane sugar, make up to 100 c.c., add 10 C.C. strong HC1, and invert as before. Cool, take 11 C.C. of this solution, neutralize, and make up to 100 C.C. This I call solution CL. Dilute 20 C.C. of the filtrate used for direct polarization, and make up to 100 C.C. This I call solution b. Take two beakers, and in each place 25 C.C. of Soxhlet's copper solution and 25 C.C. of Soxhlet's alkaline tartaric solution and 40 C.C. of water, add to one 10 C.C. of solution a, and to the other 10 C.C. of solution b. Place both over flames and bring to the boil in four minutes, and boil for four minutes longer, filter off the reduced cuprous oxide, and weigh either as metallic copper or copper oxide.The cuprie reducing power of the marmalade, calculated as percentages of invert sugar, will be found by the following formula : Cu (or CuO) from b 4 x Cu (or CuO) from a - x 100. The reason for making solution b four times as strong as solution u is that theTHE ANALYST. 125 cupric reducing power of a marmalade is somewhere in the neighbourhood of 25 per cent. Calculation of the Percentage of Glucose.-I need hardly point out that “glucose ” is not a chemical entity, but is a mixture of maltose, dextrin, dextrose, and probably intermediate compounds. The following table will give the composition of com- mercial glucoses.The first nine are taken from a paper by Weber and McPhearsou (“ Proceedings of the Eleventh Annual Convention of the Association of Official Agricultural Chemists,” p. 126) : Total solids 78.9 80.1 80.8 50.3 85-6 87.4 80.0 81.1 86-6 78.9 [uID of solids 133.3 132.9 120.6 135.4 132.1 127.8 149-3 130.3 134.9 143.1 Cupric re- g\ 56% 57-0 60.6 54.9 56.7 55.9 43.6 50.6 48.8 48.5 power of solids ... J 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Analysis No. 10 is by H. D. Richmond. The averge of these ten samples, which may be taken to fairly represent the mean coinposition of commercial glucose, is : Total solids, 81.9 ; [u],, of solids, 133.98 ; cupric reducing power of solids, 53.31. From the paper referred to, I find that Weber and MacPhearson found thzt coin- mercial glucose, on the average, gave, in a solution containing 13,024 grammes per 100 c.c., a Direct reading ...... 85.45 sugar degrees. Inverted reading . . . ... 84.9 7 , The inverted reading is done by the method described above, which must be strictly adhered to, Herzfeld’s modification having given a much larger difference. It is seen that the change on inversion is practically nil, and therefore cane-sugar can be esti- mated in the presence of commercial glucose with very fair accuracy. The average [a],, of the solids of commercial glucose (133.98) is practically twice that of cane- sugar, and it may be assumed without much error that 1 per cent. of glucose solids will polarize 2 per cent. of cane-sugar. When cane-sugar is inverted, 100 park become 105.3 : The cupric reducing power of inverted cane-sugar is therefore 105.3.The cupric reducing power of glucose solids, 53.13, is practically half this, and it may be assumed without much error that 1 per cent. of glucose will have a cupric reducing power equal to 0.5 per cent. of cane-sugar. To calculate the percentage of cane-sugar, invert sugar, and glucose in a marma- lade, the following formula3 can be derived from the facts above mentioned : C,,H2,01, + OII, = C,H,,O, + C,H,,O,. Direct - inverted reading to 144 - - 2 Cane-sugar - direct reading __ __ + 4 cupric reducing power to 4+44-- 2 100’ Cane-sugar= ~ ~ . -- -~ Inverted sugar = ___ Glucose-= 2(cupric reducing power - inverted sugar).126 THE ANALYST. I t must be borne in mind that the inverted sugar is given by all the above formuls as percentages of cane-sugar inverted, and not as percentages of actual invert sugar present, This is done for the sake of convenience, as by adding the cane and inverted sugar together the percentage of cane-sugar present will be given.As a, test analysis, a marmalade, of which the composition was unknown to me, was made up containing : Cane-sugar ... ... ... 40.0 per cent. Glucose .,. ... ... ... 20.0 ,, Direct polarization ... ... ... +61.2 at 16.5 C. After inversion ... ... ... +18*2 ,, Cupric reducing power ... ... 16.48 From these results the composition was calculated as follows by the above formulz : The figures found on analysis were as follows : Cane-sugar ... 3;:; 1 40.0 total Inverted sugar ... Glucose - . ., 16.3 =glucose containing 81.9 per cent solids = This result seems to indicate that cane-sugar, invert sugar, and commercial glucose can be estimated with sufficient accuracy in the presence of each other. The following analyses give the composition of nearly all the best known brands of marmalade on the market, the results having been all obtained by the methods given above : 19.9 per cent. 1. Moisture ... 33.3 Inverted sugar., . 25.0 Undetermined ... 4.0 100.0 Sugar ... ... 37.2 Acidity ... . . 0.5 _- 6. Water ... ... 31-3 Inverted sugar.. . 23.9 Glucose ... 8.7 Undetermined ... 1.0 100.0 Sugar ... ... 34.7 Acidity ... ... 0.4 -- 11. Water ... ... 30.7 Sugar ... ... 19.7 Inverted sugar.. . 34-1 Glucose ... 13.3 Acidity ... ... 0.6 Undetermined ... 1.6 100.0 -- 2. 33.1 42.1 21.0 0.3 3.5 100.0 7.26.6 35.6 304 5.0 0.5 0.9 -- 1oq.o 12. 31.1 32.9 17.9 14.3 0.4 3.4 100.0 -- 3. 27.7 25.6 41.8 0.4 4.5 100.0 8. 30.0 33.9 11.1 22.9 0.4 1.7 100.0 13. 40.6 31.4 21-5 none 0.5 6 0 -- -- 4. 30.6 32% 32.7 0.4 3.7 100.0 9. 25.3 22.8 38.2 11.6 0.4 1.7 100.0 28.6 44.7 21-9 none 0.6 4.2 -- -- 14. 100.0 100.0 5. 31.5 33 -2 30.0 0.5 4.8 100.0 10. 31.7 32.8 30.4 none 0.5 4.6 100.0 15. 27.7 44.0 22.9 none 0.5 4.9 100.0 --THE ANALYST. 127 16. ... Water ... ... 28.6 ... Sugar ... ... ... 24.3 Inverted sugar ... ... ... 42.8 Acidity ... ... ... ... 0.6 Undetermined ... ... ... 3.7 100.0 The sample labelled No. 8 contained added geIatin or isinglass, and the sample No. 16 was one of Messrs. Keiller’s marmalade, which had been kept for six years ; hence the abnormally high invert sugar.Nos. 11 and 12 were preserved with salicylic acid. The amount of invert sugar formed in a marmalade seems to be due to three causes : Firstly, the amount of acid present ; secondly, the length of time the cooking is continued; and, thirdly, the length of time it has been kept. The figures for undetermined matter vary somewhat, but as the error of separating and estimating a complicated mixture of sugars is thrown on this figure it is not surprising. Sugar is naturally present in oranges, and a correction has been applied for the amount of fruit-sugar present in a marmalade ; it consists in subtracting 0.1 sugar degrees from the + reading, and 0.3 from the - reading-that is, supposing the normal quantity of marmalade to have been weighed out, namely, 65.12 grammes per 250 C.C.In conclusion, I should like to express my thanks to Mr. H. Droop Richmond for help in confirming some of the results given in this paper. DISCUSSION. The PRESIDENT having invited discussion, Mr. A. C. CHAPMAN inquired what assumption Mr. Boseley made in regard to the composition of glucose in the method he had adopted. Ordinary commercial glucose (a mixture of dextrose, maltose, and occasionally dextrin) varied very much in com- position. The proportion of maltose, for instance, might be as little as 4 or 5 per cent., or as much as 25 per cent. Some samples contained no dextrin ak all, while others contained a fairly considerable quantity. I t would be necessary to assume a constant composition as a basis for purposes of analysis and calculation. Mr. HEHNER observed that an important reference had been made in the paper to salicylic acid. Salicylic acid was often found in jam, and had given rise t’o a good deal of discussion. Mr. Boseley now stated that it was added to jam solely as a meansof adulteration, and in view of this he (Mr. Hehner) thought that its presence in jam might be somewhat more vigorously condemned than hitherto. The excuse that it prevented the preserve from going bad, and that it was not particularly harmful, might justify its being passed ; but when it was distinctly understood that it also afforded a means of adding water, the matter became very serious. Mr. L. K. BOSELEY said, in reply to Mr. Chapman’s question, that the basis the calculations had been worked out upon was the cupric reducing power of the glucose, and also the [a], of the glucose solids. He was sorrynot to have had time enough to make this clear when reading the paper, but Mr. Chapman would understand that the amount of dextrin, dextrose, etc., which the glucose contained did not enter into the calculation, that being based on the average cupric reducing power, etc., of glucose.

ISSN:0003-2654    

DOI:10.1039/AN8982300123

出版商:RSC    

年代:1898

数据来源: RSC

摘要:

128 THE ANALYST. NOTE ON THE VOLUME CONCENTRATION OF CONDENSED MILK, BY A. MCGILL. THE purchaser of condensed milk, as a rule, thinks of its concentration in terms of volume rather than weight ; and values a pint of the article more or less highly as he takes it to represent more or less than, say, three pints of the milk used in its preparation. A. H. Allen (see ANALYST, xxi., p. 281) has given a formula for cal- culating, from the results of analysis, the volume concentration of any sample. His formula involves a knowledge of the specific gravity of the sample, and assumes the normal character of the milk from which the condensed article is made. I would suggest the solids-not-fat instead of the total solids as a basis for calculation of the concentration. I t is mainly in the partial or entire reinoval of the fat before manufacture that condensed inilks differ from each other ; and although, in the case of a whole milk, it makes little difference whether total solids or solids- not-fat is employed in the calculation, the error is very considerable when a skimmed inilk is in question.The following examples, taken from the analyses of Pearinain and Moor (ANALYST, xx., 272), illustrate this : Concentration based on Total Solids= 12.5 per cent. Concentration based on Solids-not-Fat = 8.5 per cent. Brand. Milkmaid ... ... , . . 3.85 ... ... 4.02 Lancer ... ... ... 3.26 ... ... 4.74 These figures are calculated by Mr. Allen's formula, in which the density of normal milk is taken as 1, and that of condensed milk as 1.28. My own experience shows that iiiost samples of sweetened condensed milk have a gravity of 1-31 to 1.33 ; and I prefer to use the number 1.03, instead of unity, as the average density of normal milk.The density of condensed milk is not easily taken upon the sample itself. I prepare a solution of 50 grammes to 250 c:c., and from tlhe density of this solution calculate that of the original sample by the formula : Original density = - -' when (a) =density of the dilute inilk. 6 - 5a' If these changes be made, the numbers already given for Milkmaid and Lancer brands will become 4.01 and 4.75, instead of 4.02 and 4.74; so that, for practical purposes, it is of little consequence which pair of numbers is used. If, however, the true density of the sample be used in calculation, while the density of normal inilk is taken as unity, the numbers become 4.13 and 4.84 respectively. The formulz used may be written as follows : Let n =solids-not-fat in normal milk., , ?zl = solids-not-fat in samples. ,, d =density normal milk. ,, d, = density of sample. ,, f =fat in milk used in manufacture. ,, f, =fat found in sample. ,, c = volume concentration.THE ANALYST. 1.29 f X . f I - 8-5 fl. 121 7% Thus, the fat percentage in the original milk used in preparing the Milkmaid brand is found to be 3.515. LABORATORY OF THE INLAND REVENUE DEPARTMEST, OTTAWA, Januayy 15, 1895. THE INSTITUTE OF CHEMISTRY. THE annual dinne of the Fellows and Associates of the Institute of Chemistry took place last night at the Trocadero Restaurant, Piccadilly Circus. The president, Dr.T. Stevenson (official analyst to the Home Ofice), occupied the chair, and the large company present included Lord Reay, Mi-. Justice Byrne, Sir J. Evans (treasurer Royal Society), Sir E. Frankland, Sir H. T. Wood (secretary of the Society of Arts), Mr. K. E. Digby, Dr. Bernard Dyer, Dr. W. J. Russell, Dr. Thorpe, Mr. T. H. Elliott, Mr. J. F. Moulton, Q.C., Mr. H. Kearley, M.P., Mr. H. H. Cozens-Hardy, M.P., Professor Dewar, Dr. J. H. Gladstone, Dr. Ludwig Mond, Mr. W. Hills (president of the Pharmaceutical Society), Dr. H. E. Armstrong, Dr. W. J. Sykes, Dr. J. A. Voelcker, Mr. Otto Rehner, Professor J. &I. Thomson, Mr. D. Howard, Mr. R. J. Friswell, Mr. T. Fairley, Dr. Corfield, Dr. Wynter Blyth, and Mr. R. B. Pilcher (secretary). Mr. Justice Byrne proposed ( ( The Institute of Chemistry,” and the President, in responding, mentioned that the register of the society now contained the names of 826 Fellows and 120 Associates, while there were over 180 registered students training for the examination at the various colleges recognised by the Institute. He looked forward to the time when professional chemists would be endowed with the power of conferring diplomas, and exercising the same restrictive functions as were already possessed by the professions of the law and physic. Other toasts followed. (Abridged from the Times,)

ISSN:0003-2654    

DOI:10.1039/AN8982300128

出版商:RSC    

年代:1898

数据来源: RSC

摘要:

THE ANALYST. 1.29 ABSTRACTS OF PAPERS PUBLISHED IN OTHER JOURNALS. FOODS AND DRUGS ANALYSIS. (Zeit. fiir Untersuch. dei- Nalzr. und GenussmnitteZ, 1898, 153.)-Ainong a collection of samples of pepper supplied by Messrs. Lewis and Peat, of London, was a variety of black pepper from Mangalore, which differs considerably from the sorts usually met with. The author is not aware if it is on the English market to any large extent, but in Germany and Austria, it is quite unknown. Its place of origin, Mangalore, is a town on the west coast of India, between Goa and Cochin, and therefore in the heart of the pepper- growing district. The pepper-corns are about 7 mm. in diameter, of a deep black colour, and either nearly spherical or somewhat egg-shaped. One hundred of the Black Pepper from Mangalore.T. F. Hanansek.130 THE ANALYST. peppercorns weigh 8.6 grammes. They possess a very powerful pepper taste and odour. The ash amounts to 3’43 per cent? The microscopic examination of the husk reveals much the same general structure as the husk of ordinary pepper. Illustrations are given showing the microscopie appearance of sections of the pepper- corns, the cells, etc. H. H. B. s. Glucose in Butter. C. A. Crampton. ( J o w . Anzer. Chem. Soc., 1898, xx., 201-206.)-The author states that the method found mo-st satisfactory by the manu- facturers for preserving butter for export to tropical countries is by the addition of considerable quantities of salt and of glucose, The following table gives the results of the analyses of three samples of such prepared butter : No.2,434. Butter cxported from the United States to Brazil. Water . . . ... 16-29 Casein (N x saij’ ... 1-19 Ash ... ... ... 7.00 Fat ... ..- ... 72.16 Glucose (by difference) . . . 3.36 No. 2,443. Butter exported t o Brazil and returned to U.S.S. 18-93 1.06 6.19 69.67 4.15 ?So, 2,460. Ucibwe Rouge exported to G iiadeloupe. 21.60 0.81 16.42 51 15 10.02 100.00 100~00 100~00 The characteristics of the fat separated from these three butters were not abnormal, though the Reichert-Meissl value of No. 2,443 was somewhat low (25.4) For this reason the Brazilian authorities rejected the butter, but; the glucose escaped their notice. A sample of the glucose used for this purpose wa8 found by the author to consist of the ordinary syrup known as confectioner’s glucose.I t contained 16.5 per cent. of water, and gave [a] D = 119.3. As to its detection in butter, it is shown that on extracting the fat with ether, and determining the casein by loss on ignition, the results are abnormally high and widely different to those obtained by calculating the casein from the amount of nitrogen; whereas with pure butter the figures are in close agreement. For a direct determination of the glucose, 10 grammes of the butter are treated with successive portions of hot water in a separatory funnel, and the resulting solution made up to 250 C.C. A slight reduction of Fehling’s solution by this solution might be due to milk-sugar or some of the albuminoid substances, but any considerable reduction must be attributed to the presence of sugar or glucose. The optical rotation can be determined in the same solution previously clarified by means of alumina cream or acid mercuric nitrate solution, This butter when returned was still passable. The figures given by the author show that either method gives reliable results. C. A. M.

ISSN:0003-2654    

DOI:10.1039/AN8982300129

出版商:RSC    

年代:1898

数据来源: RSC

摘要:

THE ANALYST. 131 ORGANIC ANALYSIS. A Colour Reaction of Ethylic Aldehyde. L. Simon. (Comptes rendus, vol. cxxv., p. 1105; through Rev. Chim. AnnZyt. a&, vol. vi. [5], p. 79.)-By adding to a dilute aqueous solution of ethylic aldehyde a few drops of trilnethylamine followed by several drops of an almost colorless solution of sodium nitro-prusside, there gradually develops a beautiful blue coloration, which is intense in the case of a 1 per 1,000 solution, and apparent down to a degree of dilution equal to -;Ls&a. No other aldehyde or ketone substance gives this reaction, neither does pure ether, although the coloration appears when the latter contains &G8 of aldehyde, Ammonia cannot replace trimethylamine, since it prevents the appearance of the coloration, c.s. and destroys it if already formed. Colour Reaction of Phenylhydrazine. L. Simon. (Comptes r e m h s , vol. cxxvi., p. 483 ; through Eev. Chim. Aizcilyt. nppZ., vol. vi. [6], pp. 79, 80.)-When phenylhydrazine solution is heated for a few moments with a few drops of an aqueous solution of trimethylamine followed by a few drops of sodium nitro-prusside, and by concentrated potash, a bright blue coloration is produced, which is greenish in presence of an excess of nitro-prusside, and deepens on adding the potash, and is converted into sky-blue if acetic acid be added as well. The coloration, which enables 5TF&G part of phenylhydrazine to be detected, is distinguishable from that produced by ethyl aldehyde (see preceding abstract) by its persistence in presence of potash, ammonia, and acetic acid; it is, however, fugitive, and disappears in about a, quarter of an hour.Whilst alcohol, ether and amnionia do not prevent the reaction, chloroform and benzene retard it, as do also mineral and organic acids previous to the addition of potash. It appears to be exclusively characteristic for phenyl- hydrazine and the derivatives of the latter substituted in the aromatic nucleus. c. s. Characteristic Colour Reaction of Cotton-seed-Oil. G. Halphen. ( A m . ClLim. AnaZyt., vol. iii. [I], pp. 9-ll.)--The development of the red coloration produced by cotton seed-oil in presence of carbon disulphide can be accelerated, so as to be utilizable for the purposes of qualitative analysis, by the presence of free sulphur in the solvent, and the addition of amyl alcohol.Equal volumes (1 to 3 c.c.) of the oil under examination, ainyl alcohol, and carbon disulphide containing 1 per cent. of dissolved sulphur, are placed in a test-tube, which is then partly immersed in a boiling brine-bath for ten to fifteen minutes. A red or orange coloration denotes the presence of cotton-seed-oil. If, however, no change is observed, another 1 C.C. of the same carbon disulphide is added, and heat again applied for five to ten minutes, this operation being repeated in the event of the result again proving negative. As little as 5 per cent. of cotton-seed-oil can be readily detected in this manner. c. s.132 THE ANALYST. Analysis of Fats. Melting-points of Cholesterin and Phytosterin. A. Bomer. (Zeit. fiir Unterszcch.der Nnhr. u?zcl Ge?zuss?nittel, 1898, 81.)-The melting- point of cholesterin from animal sources (excluding butter) fluctuates, according to most observers, between 144.5" and 146" C., and of phytosterin from vegetable sources between 131.5" and 138" C. The author has made a large number of deter- minations of the melting-points of cholesterin and phytosterin extracted from different animal and vegetable sources by the method recently published by him (Zeit. fiir Untersuch. dey Nab?.. z~?zci! Geimssmittel, 1898, 21-49 ; ANALYST, xxiii., 42), and in order to arrive at as exact results as possible, he in every case repeatedly recrystallized the products, determining the melting-points after each crystallization, until constant. The determinations of the melting-points of thirty-eight specimens of cholesterin from various kinds of pig-fat gave results as follows : First Indications First Indications of Mrltirig.of Flowing. Minimum ... ... . 146.0" 146.5" Maximum ... ... ... 148.0" 148.3" Mean ... ... ... 146.7" 147.4" According to Salkowski, the melting-point of cholesterin from butter is abnormal. He found that, even after repeated crystallization, the product, though apparently quite pure and white, melted persistently at about 5" below the ordinary melting- point of cholesterin, a peculiarity which he explained by supposing that it contained a proportion of phytosterin. The author's experiments, however, show that, if care- fully purified, butter cholesterin melts quite normally at 146" and over. Crude cholesterin prepared from butter is by no means so pure as that prepared from lard.I t contains two impurities in considerable proportions-viz., coloring matter and lecithin, and while the latter is very difficult to separate, its presence has a marked effect in reducing the melting-point of the product. The author further observes that if phytosterin were present in conjunctiou with cholesterin, its presence would certainly be revealed by the appearauce of the crystals. The determinations of the melting-points of specimens of phytosterin prepared from various vegetable fats gave results as follows : First Indications First Indications of Melting, of Flowing. Minimum ... ... ... 135.5" 136-0" Maximum ... ... ... 141.0" 141.5" Mean ... ... *.. 137.5" 137.8" Experiments upon the melting-points of mixtures of cholesterin and phytosterin showed that the melting-point of a mixture approximates to that obtained by calcu- lation from the melting-points of its components, though a mixture of 3 parts of phytosterin and 1 of cholesterin gives a slightly lower, and a mixture in the reverse proportions a slightly higher, melting-point than the calculated.Mixtures of cholesterin and phytosterin cannot be separated into their components by crystal- lization. The determination of cholesterin may be found useful for the following purposes : 1. The detection of vegetable oils in cod-liver-oil. 2. The detection of cotton-seed41 in lard, etc.THE ANALYST. 133 3. The detection of margarine in butter, in cases where the Reichert-Meissl Margarine being rarely free from vegetable oils, the determination of method fails.phytosterin affords a valuable means for its detection. H. H. B. S . Technical Analysis of Bone-fat. A. A. Shukoff and P. J. Schestakoff. (Chenz. Rev. Fett PL. Harx-hd., vol. v. [l], pp. 5-8 ; [a], pp. 21-23.)-I. Estimation of Water.- The ordinary method of determination, by drying 5 grammes of fat at 100" to 110" C. in the oven until of constant weight, is adopted. The time occupied depends on the purity of the f a t ; bone fats containing lime salts often require over twenty-four hours owing to the tenacity with which these impurities retain moisture. The Tate method of heating at 130" C. until the evolution of gas ceases gives results below the truth. When lime salts are present, the use of a current or" carbon dioxide for accelerating drying is not feasible, owing to the frothing produced, 2.E'xtm?zcous Admixtures .-These comprise (organic) dirt, sand, calcium phos- phate, and lime soaps. In the ordinary method of estimation by dissolving the fat in petroleum spirit or carbon disulphide, coiisiderable differences exist in the amount of insoluble residue, the influential factors being the solvent, the temperature, the duration of the operation, and the presence or absence of water. Carbon disulphide dissolves more of the lime salts than does petroleum spirit, and in most cases reprecipitation occurs on standing or cooling. Undried fat leaves a much larger proportion of lime salts as insoluble residue than dried fat. Apart from the question whether, in view of their high percentage of fatty acid, lime soaps can properly be regarded as impurities (though their presence is in- convenient when the fat is to be converted into soap), the solution method does not give accurate results, and other means must be employed (see §s 3 and 4).3. Ash.-This must be determined by combustion of the entire fat, and not merely from the residue left by solvents. The principal constituent being calcium carbonate and oxide, the amount of calcium can be determined by titration, and the amount of lime soaps by calculation from the result, 260 being taken as the average molecular weight of the fatty acids. When sand, calcium phosphate, etc., are present, a quantitative analysis of the ash must be made, but this is seldom necessary 4.Direct Estimation of tlze Pure Fat.-In place of the usual, but erroneous, method of determining this chief constituent by difference, the authors propose the following : About 10 grammes of fat are gently heated, with frequent shaking, for about an hour on the water-bath, with 3 to 5 drops of strong hydrochloric acid to decompose the lime soaps, and are then dissolved in 40 C.C. of light petroleum spirit. The solution is decanted from the acid through a tared filter, and is then distilled along with the (two or three) washings to drive off the bulk of the solvent, the pure fat thus obtained being finally dried at 100" to 110" C., with the acid of a current of carbon dioxide, until constant. The residual acid and dirt are rinsed with water through the same filter, and the impurities determined therefrom.134 THE ANALYST.Water can be estimated by difference to check the results obtained by direct determination. 5. Unsapom&xble Matter.-The results furnished by the Allen and Thomson method are higher than by that of Morawski and Demsky, owing to the more complete extraction of the cholesterin. The former method, however, is inaccurate owing to the solution of a portion of the soap in the ether employed, and the authors therefore recommend the following modification : Five grammes of fat and 25 C.C. of 8 per cent. alcoholic caustic soda are evaporated to dryness, taken up with 80 C.C. of water and extracted with an equal volume of ordinary ether in a separating funnel, the separation of the liquids being faciIitated, if necessary, by the addition of alcohol, but avoiding an excess of the latter.After the third extraction the ethereal solution is evaporated without wash- ing, the residue is rendered alkaline by normal caustic soda and re-dissolved in petroleum spirit, which solution yields on filtration and evaporation an ashless residue. The technical importance of the unsaponifiable residue depends on the use to which the fat is put; for soap-making it must be looked on as an impurity and deducted from the total fat, whilst for the stearin industry the presence of cholesterin is no drawback. The solidifying-point of the fatty acids is determined by the original Dalican method. c. s. Precipitation of the Albumoses by Zinc Sulphate. H. Baumann and A. Bomer. (Zeit.fiir Untersuch. der Nahr. uizd Genussmittel, 1898, 106.)-In a former paper by one of the authors (A. Bomer, Zeit. anal. Chemie., 1895, 562) zinc sulphate was proposed in place of ammonium sulphate as a precipitant for the albumoses The authors have further investigated the subject, and arrived at the following results : 1. If 1 C.C. of dilute sulphuric acid (1: 4) be added to 50 C.C. of solution, the albumoses are precipitated as well with zine sulphate as with ammonium sulphate. 2. Ammonium salts, tyrosine and kreatine are not precipitated by zinc sulphate. Leucine is thrown down in small quantities, but considering the small amount present in meat preparations the error is not material. Leucine and tyrosine are, on the other hand, both separated in considerable quantities by ammonium sulphate.3. The meat bases are as completely separated by phosphomolybdic acid in the filtrate from the zinc sulphate precipitation as they are in an aqueous solution, and the peptones are even more completely separated, 4. The filtrate from the precipitation of the albunlases can be precipitated directly with phosphomolybdic acid, thus avoiding the error caused by the different nitrogen contents of the albumin and gelatin albumoses. 5. Ammonia and kreatine are separated from solutions by sodium phosphomolyb- date with almost quantitative exactness. The authors propose the following method for the determination of the albu- nioses and peptones in meat extracts and peptone preparations : Fifty C.C. of solutionTHE ANALYST. 135 containing about 1 gramme of dry substance are freed from insoluble and coagulable albumin, and mixed with 1 C.C. of dilute sulphuric acid (1 : 4) and sufficient zinc sulphate added to supersaturation. The precipitate is filtered off and washed with it slightly acidified saturated solution of zinc sulphate, and the nitrogen determined by Kjeldahl’s method. I n the filtrate the peptones, meat bases, and ammonia are precipitated by sodium phosphomolybdate. The precipitate is filtered off, and the nitrogen also of this determined by Kjeldahl’s method. The ammoniacal nitrogen is determined, either in the aqueous solution, or, better still, in a second phospho- molybdate precipitate by distillation with magnesia. The amount so found being deducted from the total nitrogen in the phosphomolybdate precipitate gives by dif‘ference the nitrogen present as peptones and meat bases with, under certain circumstances, small quantities of leucine. H. H. 13. S.

ISSN:0003-2654    

DOI:10.1039/AN8982300131

出版商:RSC    

年代:1898

数据来源: RSC

摘要:

THE ANALYST. 135 INORGANIC ANALYSIS. Volumetric Determination of Antimony. H. Causse. (Comptes wm,ZzLs, vol. cxxv., p. 1100; through Rev. Chirn. AmZyt. appZ., vol. vi. [3], p. 31.)-The method is based on the conversion of antiinonious acid into antimonic acid by iodic acid. As reagents the author employs: (1) Iodic acid solution, containing 200 grammes per litre, prepared beforehand in order to allow the barium iodate, almost always present in the comniercial acid, to subside. (2) Decinormal sodium thio- sulphate solution. (3) A 20 per cent. solution of potassium iodide. (4) Fresh starch paste. Antimony oxide (0.50 to 0 60 gramme) is placed in the apparatus used by Mohr or Freseaius in estimating iodine, and 20 to 25 C.C. of iodic acid are added, 10 C.C. of potassium iodide being placed in the tube condenser.On heating gradually to boiling, the iodine is liberated, absorbed by the iodide solution, and the iodine determined by titration with sodium thiosulphate. c. s. Estimation of Metallic Iron in Iron reduced by Hydrogen. Dr. Schmidt. (Vers. deutsch. Nuturf. u. Aertxe ; through Rev. Chim. Anulyt. appl., vol. vi. [31, p. 32.) -0.4 gramme of reduced iron is attacked in a 100 C.C. flask' by 2 to 2.5 grammes of iodine (accurately weighed) in presence of 5 to 10 C.C. of water; the iron alone is dissolved under these conditions, leaving the oxide. One gramme of potassium iodide is then added and the liquid made up to 100 c.c., the excess of iodine being titrated with sodium thiosulphate. c. s. Contribution to our Knowledge of the Rare Earths. L.Haber. (Monats- heft fiir Chemie, xviii., 687.)-The author has studied the behaviour of the rare earths to chromic acid, potassium bichromate, sodium acetate and formate, and to tartaric, citric, and malic acids. The various reactions are summarized in the following table :136 Tartaric Acid. THE ANALYST. Citi-i? nInlic Acid. I Acid. Potassiiim or Sodium Bichromate. Sodium Acetate. Sodium Formate. a flocky condi- tion on I soluble in pletely, on boiling. Precipitate is white and flocky, and soluble in sodium acetate and form ate. like the preced- ing. Sol- uble in sodium acetate and forniate. cultyfrom , concen- ~ trated I solutions. I I ~ I I 2hromic Acid. Thorium - Precipitates on boiling with diffi- culty and incoxr- pletely. Precipitate is orange- yellow and distinctly crystalline, PrecipitateR easily from sufficiently diluted solutions on boiling.Precipita- tion is in- complete, and preci- pitate in- soluble in water. Precipitates 1 Precipitites from not with diffi- too dilute I culty on solutions boiling. on boiling. I Precipitate Precipitate is white is white and crys- and crys- talline. talline. Precipi- tates on boiling as R white, cry stal ~ line precipi- tate ; solublein. sodium acetate and for- mate. Zirconium Precipitates moder- ately, easily, and completely on boiling. Precipi tat€ orange- yellow and flocky. Precipitates in a focky condition, very easily on boiling. Precipitates very easily and com- pletely on boiling. Precipitate is white and focky. Precipitates ' Precipi- incom- I tates Precipi- tates easily o n boiling.Flocky : Precipitates very easily on boiling. Precipitate is white and flocky. ylcjurly 111 cu fine flocky I condition ; soluble in sodium 1 acetate and ' in excess of ~ precipitant. precipi- tant, , Not precipitated, Not precipitated. Not precipi- tated. Not precipi- tated. Cerium Precipitates incom- pletely from con- centrated Not precipitated. Not precipitated. 1 solutions. , precipitate is beauti- ~ fnlly crya- ~ talline. Not precipitated. Not precipi- tated. Not precipi- tated. Lanthanum hTot Not ' Precipitates Not precipitated. precipitated. incom- i precipitated. I ~ from con- pletely centrated 1 Beautifully 1 crystalline. , I 1 solutions. I Didymium Not ~ Not ' Kot ~ PreciDitates Not Not xgt precipi- tated. precipitated.precipitated. precipitated. incom- I precipitated. precipi- pletely 1 i tated. from con- 1 I centrated I I Y t t r i a - - Not precipitated. Not precipitated.THE ANALYST. 137 Thorium and zircoiiium are both characterized by the formation of basic salts with the organic acids; but whereas the thorium salts appear to be of constant composition, the zirconium compounds by continued treatment with water undergo a gradual change towards the condition of hydrate. H. H. B. S. APPARATUS. A New Separating Funnel. E. Spaeth. (Zed. fiir Untersuch. cler Nahr. m c l Genussnzittel, 1896, 96.)- The funnel is provided with a two-way stopcock, the channels of which are separate and distinct from each other. One channel is straight and the other oblique, and each connects with a separate efflux tubulure, as shown in Fig. A. It is also provided with a stand, shown in Fig. B. In using the funnel it is obvious that, after the lower layer of liquid has been drawn oft' through the vertical channel, the upper layer can be run out through the other, which will be quite clean and uncontaminated. H. H. B. S.

ISSN:0003-2654    

DOI:10.1039/AN8982300135

出版商:RSC    

年代:1898

数据来源: RSC

摘要:

THE ANALYST. 137 MISCELLANEOUS. The following article appeared in the Times of April 18, 1898 : “POLLUTED WATER AND SOMERSET HOUSV. ‘( ( 1 . ~ 0 ~ A CORRESPONJIENT.) “After the experiences of Maidstone last winter, it might be expected that at least no obstacles would be placed in the way of the sanitary authority in dealing with all possible sources of danger within their jurisdiction. The public will, therefore, learn with astonishment that their efforts to.do their duty by the community and to prevent the continued use of water from a dangerous source have been frustrated by the action of the local justices, with the assistance of two Government officials attached to the Inland Revenue Department. The whole case is so irregular, and so important to all sanitary authorities, that it deserves the widest publicity.“ I n Maidstone, as in most other towns, there are, in addition to the public water supply, a certain number of wells still in use. One of these, situated in Orchard Street, supplies four houses in that street which have not had the public water laid on. I n the immediate neigh- bourhood fourteen cases of typhoid fever occurred in ten houses, distributed on all sides of the spot where the well is, and in dangerous proximity to it. The water, on being analysed by the The facts are briefly these :138 THE ANALYST. medical officer of health-who is also analyst to the county of Kent, and an exceptionally competent authority-showed signs of organic impurity, not to an alarming extent when taken by themselves, but more than sufficient to prove danger when taken in conjunction with the situation of the well and the known defective condition of the house-drains near it.The medical officer, guided by all the circumstances, condemned the water for drinking purposes, as every Competent officer must have done in his position ; but he did not recommend compulsory closure of the well, hoping to attain the same end more easily by persuasion. The wording of the Act makes it very difficult to obtain an order for compulsory closing except on chemical grounds, and in this case the chemical evidence was of less weight than the other conditions, and, apart from them, susceptible of a more favourable interpretation. However, the sanitary authority, actuated by a laudable anxiety to protect the town, applied for a closing order.I t should be observed here that there is no reason why the well should not be closed, as the public water-supply is laid on in the street. The case came on for the first time on January 25, when it was adjourned for the defendant's chemist to attend. At the second hearing, on February 15, two chemists appeared for the defendant, and pronounced the water wholesome on chemical grounds, as they were quite entitled to do. The results of their analysis agreed with those of the medical officer ; the difference lay in his interpretation, which was influenced by knowledge not within the reach of the other chemists. The magistrates then took a most singulilr step. They adjourned a second time, and ordered a sample to be sent to the Inland Revenue Depart- ment at Somerset House.A t the third hearing, on March 15, a certificate was produced, signed by two officials in the Government laboratory, but not by the principal. The certificate, after giving the results of the analysis, which agreed in the main with those previously made, went on to say : ' From a consideration of all the results of the analyses there are grounds for stating that th? water is not liable to contamination from the immediate neighbourhood of the well, and, although the water on account of its hardness could not be recommended for general domestic purposes, we are of opinion that its use for potable prposes is not likely to prove injurious or daiigerous to health.' The magistrates thereupon dismissed the application, with costs against the sanitary authority.The public importance of the case lies in the fact that wells of this kind are one of the most dangerous and troublesome sources of disease with which sanitary authorities have to deal. It is difficult enough to get them closed a t anv time-under thc law, but if the analysts of Somerset House are to be made the arbiters-which is not provided by the law-it will clearly become impossible. Though doubtless highly competent in their own line, they have nothing to do with water, and still less to do with sanitation. By the Food and Drugs Act of 1875 the Inland Revenue Laboratory was appointed referee for the analysis of food and drugs in disputed cases, but water is expressly exempted by section 2 of the Act. Somerset House therefore, has no official or legal status in the present case.The terms of the certificate quoted above are a sufficient proof that i t ought not to be allowed to usurp any such status. An analyst has a perfect right to say that a sample of water submitted to him is wholesome and fit to drink, but no one possessing an elementary knowledge of sanitary science would venture to certify, on chemical grounds, that a water is ' not liable to contamination,, or ' not likely to prove dangerous to health.' Those are questions the answer to which depends on the conditions surrounding the source of the water. A perfectly pure water may obviously be liable to dangerous pollution if the circumstances favour it. The greatest authorities have long ago laid down the axiom, which is now universally accepted, that chemical analysis can only be accepted as positive evidence of danger, not as negative evidence as to its absence.To use the words of the late Sir George Buchanan : ' The chemist call tell us of impurity and hazard, but not of purity and safety. For information about these we must go, with the aid of what the chemist has been able to teach us, in search of the conditions surrounding the water sources.' The same principle has been further laid down by the Local Government Board in relation to wells precisely similar to the one in question-' We must go beyond the laboratory for evidence of any drinking water being free from dangerous organic pollution., When a water actually shows traces of organic impurity, it is an astonishing subversion of established principles for any responsible person to give a certificate of safety, not only in the present but for the future, on the strength of analysis alone and without taking the surrounding conditions into account.Considering what they are in the case of the Orchard Street well, one can only describe such a certificate as reckless. The danger to be apprehended is that specific pollution, which there is reason to believe has soaked into the ground, will gradually find its way into the well. The results of the three analyses confirm that danger. There is no discrepancy between them, but the two later ones indicate somewhat more impurity than that originally made, and point to a process o f progressive pollution. The medical officer has recornmended his committee to apply for the intervention of the Local Government Board, which is the proper authority to decideTHE ANALYST. 139 the case ; and meanwhile the action of the Somerset House analysts is to be brought up in the House of Commons immediately.The interference with the sanitary administration of the country by a Government department which possesses neither authority nor knowledge of the subject is wholly mischievous. I n Maidstone alone there are several other wells which ought to be closed, but in face of recent proceedings it is obviously useless for the sanitary authority to take action.” [The following table, extracted from a report by Mr. Matthew A. Adams, F.R.C.S., F.I.C., of the case referred to, shows the local standard for unpolluted ragstone water, the results of the analysis of the water from the well condemned by Mr.Adams, the results of the analysis made by Mr. Gregory on behalf of the owner of the well, and the results of the analysis made by the chemists of the Inland Revenue Department. A full copy of the report made by the Government chemists is also appended.] WATER ANALYSIS-REPORT. Total solids . . . . . . . . . Chlorine . . . . . . . . . . . . Nitrogen as nitrates . . . . . . Free ammonia . . . . . . . . . Albuminoid ammonia . . . . . . Oxygen absorbed in + hour ... Loss on ignition . . . . . . . . . 9 ,, in 4 hours ... H&dness, total . . . . . . . . . ,, permanent . . . . . . Appearance in 2-foot tube ... Smell . . . . . . . . . . . . Nitrites . . . . . . . . . . . . Phosphoric acid .. . . . . . . . Local Standard for Ragstone Water Conduit Supply. 32.89 2-51 2-30 -466 .005 -015 *om -018 17.4 6-5 Clear p. blue None Trace ADAMS. Sept. 17, 1897. 53.6 2-0 3.4 1-14 -00 *05 -01 3 ‘018 23.1 15.6 Greenish blue, rather dirty. None Slight trace. GEEGOHY. Dec. 2 , 1897. 52.0 ? 3.01 1.840 -02 *03 -0096 33.6 SOMERSET Hovss. J4’eb. 16, 1898. 54.1 ? 2.7 1.81 -0 1 *C64 .006.3 34.0 20 0 Clear, colourless None Trace Trace All results arc given in grains per gallon, except free and albuminoid ammonia, which are in parts per million. GOVERN XES T LABORATORY, SOMERSET HOUSE, LONDON, W.C. The sample of water referred to in your letter of the 16th ultimo, and stated on label to have been obtained from “ Orchard Street,” on “ 16th of February, 1898,” was received here on the following day, securely sealed.The water was found to be colourless, cleay, and odourless. We hereby certify that we have analysed the water, and declare the results of our analysis to be as follows : . . . . . . . . . . . . :::!4 Parts per Chlorides (stated as sodium chloride) . . . . . . = 4-45 Grains per . . . . . . . . . . . . . . . 100,000. . . . . . . . . . . . . . . . gallon. 1 1 Albuminoid ammonia - - Free ammonia - - Oxygen consumed = -009 Tolal solids (dried at 212” F.) = 54.1 Nitrates (stated as nitrogen) . . . . . . . . . = 1.81 Nitrites . . . . . . . . . . . . . . . . . . = trace. . . . . . . . . . Total hardness . . . . . . . . . . . . . . = 34.0 Degrees per Permanent hardness . . . . . . . . . . . = 20.0 [ Gallon.140 THE ANALYST. Judging from the figures shown under the terms ‘‘ albuminoid ammonia ” and ‘‘ oxygen consumed,” the water is regarded as of fair quality, and the results in these respects compare favourably with those obtained from samples of water drawn from the mains of the London Water Companies during the month of December. The proportion of nitrates is rather high, but having regard to the character of the mineral constituents of the sample, it does not indicate that the water is exposed to organic contamination.The amount of chlorides for so hard a water is not regarded as excessive. From a consideration of all the results of the analysis, there are grounds for stating that the water is not liable to contamination from the immediate neighbourhood of the well ; and although the water, on account of its hardness, could not be recommended for general domestic purposes, we are of opinion that its use for potable purposes is not likely to prove injurious or dangerous to health.As witness our hands this Eleventh day of March, 1898. The Clerk to the Magistrates, (Signed) R. BANNISTER, Maidstone. G . LEVC-IN. [On Thursday, April 21, a question was put in the House of Commons to the The following is a report of the Secretary to the Treasury on the case referred to. proceedings.] HOUSE OF COMMONS, Thurstluy, April 21, 1898. Mr. HENRY J. WILSON asked the Secretary to the Treasury, in view of the fact that the chemical officers of the Inland Revenue are appointed referees in disputed cases of adulteration under the Sale of Food and Drugs Act, and that water is specially excluded from the operation oE that Act under Clause 3, would he state whether it was in any way the duty of the chemical officers to undertake the analysis of water for sanitary purposes, and act as referees in disputed cases ; aud under what authority the chemical officers of the Inland Revenue recently analysed the water taken from a well at Maidstone, known as Prosser’s Well, and in their report expressed the opinion that the water was not liable to contamination ? Whether, as a consequence of such report, the application to the Court to close the well was refused ‘I‘ \Vas he aware that this well is in close proximity to houses in which no less than fourteen cases of enteric fever occurred during the recent epidemic ? And whether, seeing that the report was not signed by the chief of the laboratory, the action of these chemical officers was sanctioned by the responsible authority ? I1Ir.HANBURY : Under section 70 of the Public Health Act, 38 and 39 Vict., cap. 55, the magistrates are empowered, if they see fit, to cause water of which complaint is made to be analysed at the cost of the local authority. I n cases of difficulty magistrates occasionally ask for the assistance of the Government laboratory, and it has been the practice for many years, when such assistance is asked for by. the Court, to undertake an analysis of the water. I n the present instance, the justices a t Maidstone requested the assistance of the Government laboratory, and it was given in accordance with the usual practice. With regard to the latter part of the question, I understand that evidence as to the possibility of danger arising from the local surroundings of the well was given before the Court by the Medical Officer of Health, and that the magistrates, on consideration of all the evidence before them, decided to refuse the application. The action of the laboratory officers was not specially sanctioned by the Board of Inland Revenue in the particular instance. Hut these officers undertook the analysis n t the request of the magistrates, in accordance with a practice which has for years existed with the approval of the Board. Mr. JOHN ELLIS : Is the right hon. gentleman aware that the report which the oficers drew up went far in excess of anything with which they were justified in dealing? Mr. HANBURY : I think their report would go perhaps beyond their powers (hear, hear). [The Times of April 19 draws attention to a somewhat similar case, reported in the ANALYST for October, 1893.1

ISSN:0003-2654    

DOI:10.1039/AN8982300137

出版商:RSC    

年代:1898

数据来源: RSC