摘要:

THE ANALYST. 33 ABSTRACTS OF PAPERS PUBLISHED IN OTHER JOURNALS. ___---_ ___ FOODS AND DRUGS ANALYStS. (Zeit. fiir Untersuch. der Nahr. ztnd GenussmitteE, 1898, 678-683.)-The following method is proposed : 300 grammes of milk are weighed and transferred to eight test-glasses 15 cm. long by 1.5 cm. wide. These are then plrtced in a centrifugal apparatus, which is rotated at a speed of about Determination of Dirt in Milk. R. Eichloff.34 THE ANALYST. thirty revolutions a minute for five minutes. The dirt settles completely to the bottom. The cream and the greater part of the milk are now carefully removed, leaving the sediment undisturbed, and the remainder of the milk with the sediment is then washed out into a fresh tube ahd again centrifuged. The sediment is finally filtered off, with the help of a filter-pump, through a dried and weighed asbestos filter-tube, which is then thoroughly washed, dried, and re-weighed. H.H. B. S. On the Changes which take place in Milk Fat during the Ripening of Cheese. A. Eirsten. (Zeit. fur Untersuch. der Nahr. und Genusmittel, 1898, 742.)- The results obtained are shown in the following table. They are in every case the mean of duplicate experiments : Reichert- 1 I I 1 Meissl- I Number 1 Refracto- 1 Wollny meter Number Days Number at (c.c. EaO I Date. I 1 Ripening* I 250 c. I for 5 Grammes of fat). 1 2. 3. 4. 5. 17, 5, '96 27, 5, '96 3, 6, '96 10, 6, '96 17, 6, '96 2* 3. I 15,10,'96 2110,'I 1.. 25, 2, '97 2. I 24, 8, '97 1 1. 7, 1, '97 2. I 3, 11, '97 I 0 10 17 24 31 Kottstor- fer Num- ber (Milli- grammes, KHO re- quired for saponify- ing 1 Gramme).Hehner Number (Insoluble Fatty Acids from 100 Parts of Fat), I.-FAT FROM CAMEMBERT CHEESE. 27.1 ::'? 1 27.1 52.7 26-6 52 *7 26.6 52.4 1 26.9 227 227 226 225 225 87.6 87.2 87.7 87.4 87 -4 II.-FAT FROM NEUFCH~TEL CHEESE. 0 53.7 29.1 226 87.3 18 31 III.-FAT FROM TILSIT FAT CHEESE. 0 181 0 300 Remarks. Cheese ripe. Cheese over- ripe. Cheese ripe. 52.2 27.9 226 87.7 52.1 1 27.3 1 224 I 87-4 [ Cheese ripe. 53.1 27.5 229 88.4 52-4 1 27-5 I 227 1 88.1 I Cheese ripe. IV.-FAT FROM DUTCH CHEESE. H. H. B. S. Detection of Cane-Sugar in Wine, Saccharine Liquids, etc. G. Papasogli. (Giorn. di Farm. di Trieste, 1898, iii., 301 ; through Chem. Zeit. Rep., 1898, 320.)- An aqueous solution of cane-sugar gives a fine permanent amethyst colour when it is mixed with a cobalt salt and a small excess of caustic soda, and the tint is visible even in 0.05 per cent.solutions. Grape-sugar yields a blue which rapidly bleachesTHE ANALYST. 35 and finally becomes dirty green. Dilute glycerin only produces a faint green. SoIutions containing 20 per cent. of alcohol, 10 per cent. of cane and 10 per cent. of grape sugar respectively, coloured with caramel, were prepared. 15 C.C. were decolorized with 0-5 gramme of animal charcoal, filtered, treated with 0.5 C.C. of a 5 per cent. solution of cobalt nitrate, shaken, and then 2 C.C. of 50 per cent. caustic soda were added: the reactions appeared in every case, The amethyst colour characteristic of cane-sugar can be recognised even when the sugars are composed of 9 parts of grape to 1 of cane sugar.Wines must be bleached with lead acetate to remove colouring matter and tartaric acid. Condensed milk may be diluted with twice its volume of water, and treated with lead acetate. Gum and dextrin must be removed either with the normal or ammoniacal acetate of lead. F. H. L. The Detection of Starch in Black and White Mustard Seed. J. W. Lloyd. (Amer. Jozw. Pharm., 1898, Ixx., 433-439.)-The ordinary method of testing for starch by adding iodine solution to the aqueous decoction may fail with black mustard, owing to the liberation of mustard oil when the mustard comes in contact with water. This oil combines with the iodine, and when only a small quantity of starch is present no blue colour is obtained. The author has found that copper sulphate has the property of preventing the formation of the oil of mustard even when used in a solution of 0.2 per cent.strength, and also that on boiling the mustard seed with a solution of potassium iodide the same result is attained. C. A. M. ____ - ~_ The Estimation of Gelatin in Gums and Food Substances. A. Trillat. (Ann, de Cliim. Anal. AppZ., 1898, iii., 401,402.)-The property which formaldehyde possesses of forming insoluble compounds with proteid substances was applied by Beckmann (ANALYST, xx., 44) to the estimation of gelatin and albumin in peptones. A similar process is here advocated for the detection and estimation of gelatin in general, and especially when mixed with gums. The substance under examination is dissolved in water, the insoluble matter removed by filtration or decantation, and the solution evaporated to the consistence of a syrup.About 1 C.C. of commercial formalin is then added, and the evaporation continued till the mass becomes pasty. The residue is taken up with boiling water, which dissolves the gum and leaves the insoluble gelatin compound. After standing for twenty-four hours, the clear or slightly opalescent supernatant liquid is decanted, and the precipitate washed with boiling water, dried on the water-bath, and weighed. In a test analysis of a mixture consisting of 85 grammes of gelatin, 20 grammes of gum arabic, and 10 grammes of sugar, the gelatin was determined within 1 per cent. of the actual quantity. I n all cases the sabstance should be brought .to a pasty consistence before adding the formaldehyde, since in a dilute solution no precipitate is obtained.The gelatin of the jellies of commerce is determined in a similar manner. C. A. &I.36 THE ANALYST. Glazed Coffee. E. Hanausek. (Oesterr. Chezn. Zeit., 1898, i., 482.)-A new substance for glazing coffee-berries, in order (so the makers assert) to prevent loss of aroma and of caffeine, and improve the material commercially, chemically, and physiologically, consists of shellac. This is being put on the German a d Austrian markets in small angular orange fragments by G.iSchneider Nachfolger, of Ludwigs- hafen a/R., and is to be employed in amounts of 0.5 to 1-0 per cent. according to the time of preservation desired. F. H. L. The Occurrence of a Ptomaine in Coffee.S. Bein. (Zeits. nngew. Chew&., 1898, 658-661.)-A sample of coffee which had caused symptoms of poisoning in the members of a family which had drunk the infusion was examined by the author. I t was found to contain none of the usual metallic or alkaloidal poisons, and was free from artificial beans. It consisted of a mixture of black, over-burnt beans, including fragments of husks, etc., with about 18 per cent. of beans of a lighter colour, containing about 18 milligrammes of caffeine in 100 grammes. The black part of the mixture contained no caffeine, and had a coating on the surface in which was 0.42 per cent. of sodium chloride. On testing, the coffee gave indications of the presence of a ptomaine. As to the origin of the ptomaine, the following explanation is suggested : There are in cominerce a number of worthless products, consisting of mixtures of various kinds of spoilt coffee, such as that damaged by sea-water, etc., and known as L‘ Triage.” These are commonly mixed with a sinall proportion of a better substance, in order to render the article saleable as coffee.Since normal coffee only contains about 0.01 per cent. of sodium chloride, the author regarded the presence of the large percentage of that salt in the black part of the mixture as proof of its having been damaged by salt-water in transit. If such coffee were then stored in a damp con- dition in a badly-ventilated room, a decomposition of the proteid substance of the bean would soon be brought about. That under these circumstances ptomaines may be produced was proved experi- mentally.The authors suggest as a further cause, the roasting of the damaged coffee until black, with the object of concealing its decomposed appearance. On over-roasting, deep-seated changes occur; there is decomposition of the fat, of the proteids, of the coffee-tannin, and of the woody fibre, and bodies with objectionable smell are produced in considerable quantity. From the proteids especially pyrrol substances are derived, and these do not escape completely, but are partially condensed on the beans. The caffeine also is &destroyed, and methylamine and its derivatives are formed in sufficient quantity to impart their characteristic objectionable odour. From an experimentally over-roasted coffee the author prepared an aqueous extract, from which he succeeded in isolating pyrrol bodies and amine bases.The fact that no caffeine was found in the black portion of the coffee mixture can thus be accounted for by too high a roasting. The author points out that these products of over-roasting (amine bases pyrrol derivatives, stc.) are capable of producing very similar symptoms in animals to those produced by the products of putrefaction, even when in very dilute condition. c. A. M.THE ANALYST. 37 An Adulterated Gamboge. J. F. Woolsey. (Aiiber. Jozcr. Plzarm.) 1898, lxx., 446)447.)-Powdered gamboge as usually obtained is of a bright orange yellow colour, and contains 70 to 80 per cent. of resin, 3 to 4 per cent. of ash, 4 to 6 per cent. of moisture and gum, The trace of starch usually met with is not regarded as an adulteration, and is due to the method of collecting and packing. The author has recently met with a sample of a dull ochre colour, which was heavily adulterated. On treatment with 95 per cent. alcohol less than 40 per cent. dissolved. The added substance was found to consist of starch or flour (cf. ANALYST, xxi., 266). C. A. M. A good gamboge contains 75 per cent. of resin. - ~- -- -~ . _ .

ISSN:0003-2654    

DOI:10.1039/AN899240033b

出版商:RSC    

年代:1899

数据来源: RSC

摘要:

THE ANALYST. 37 ORGANIC ANALYSIS. Detection of Iodoform in Aqueous Fluids. L. von Stubenrauch. (.hit. f i i ~ Uiztersmh. der ATalir. z~7icl Geizr~ssmittel, 1898, 737.)-The method proposed by the author rests upon the following experiment. Two equal portions (one or two crystals) of iodoform are mixed into an emulsion with equal quantities (3 to 5 c.c.) of water. One portion is reduced by warming with zinc dust and a drop of acetic acid and afterwards filtered, whilst the other portion is left unreduced. On now adding a single drop of nitric acid and a little starch solution to each portion, a blue colour is produced in the reduced portion, but not in the other, It is necessary to limit the nitric acid added to a single drop. If a large quantity be used, the iodoform is decomposed and the blue colour produced without the reduction with zinc dust and acetic acid.On applying the test, if a blue colour be produced on addition of a drop of strong nitric acid and some starch, potassium iodide, hydriodic acid, or a soluble, easily decomposable organic compound of iodine may be present ; but if, on the contrary, the blue colour appear only after reduction with zinc dust and acetic acid, the presence of iodoform is indicated. A solution of iodoform in water behaves in the same way as an emulsion. A difficulty, however, arises when hydriodic acid, an iodide of an alkali metal, or a soluble organic compound of iodine, is present in conjunction with iodoform. In this case the test is only available when the proportion of the other bodies to the iodoform is relatively small, so that the difference in the depth of the blue colour produced before and after reduction is distinctly apparent.The presence of albumin, except in very small quantities, also interferes with the test. The author's experiments with the method show that iodoform taken internally is not excreted as such in the urine, but is converted into an organic iodine compound or into an iodide of an alkali metal. H. H. B. S. Preparation of a Standard Solution of Ethyl Aldehyde. X. Rocques. (Aiznal. de C'lzim. ilncd., 1898, iii., 365.)-The preparation of an alcoholic solution of aldehyde for use as a standard in the colorirnetrical determination of aldehyde is not an easy matter, owing to the readiness with which polymerization occurs and the difficulty of obtaining a pure substance.The author obviates this difficulty by using aldehyde .ammonia CH, - CH,NHs P O38 THE ANALYST. as the starting-point. This substance, as met with in commerce, is in the form of rhombohedra1 crystals melting at 70" to 80". It is very soluble in alcohol, is insoluble in ether, and is decomposed by dilute acids with the re-formation of aldehyde. It is purified by trituration in a mortar with successive portions of anhydrous ether, the liquid being decanted each time. The final residue is dried in the air, and afterwards in wacuo over sulphuric acid. 1,386 grammes of the dry compound are diisolved in about 50 C.C. of pure alcohol (96 per cent.), and 22.7 C.C. of normal sulphuric acid (mixed with more of the same alcohol) added, an immediate precipitate of ammonium sulphate being formed.The liquid is made up to 100 C.C. with the alcohol, and an additional 0-8 C.C. added to compensate for the volume of the ammonium sulphate. It is then Elhaken, allowed to stand overnight, and filtered. The filtrate contains 1 per cent. of aldehyde, and is diluted with the necessary quantities of water and 50 per cent. alcohol, so as to obtain a solution containing 50 inilligrammes in a litre of 50 per cent. alcohol. C. A. M. Reaction between Ferric Chloride and Phenol in presence of Alcohol. F. Peters. (Zeits. angew. Chem., 1898, l078.)-It is generally believed that the violet colour produced when ferric chloride is mixed with an aqueous solution of phenol does not appear if the latter be dissolved in alcohol.The author finds that on dropping a 10 per cent. aqueous solution of ferric chloride into a solution of phenol in dilute spirit, the colour is does not exceed 3.19 v/v, or reaction becomes indistinct, not prevented from appearing if the proportion of alcohol 2.53%; but as the amount rises to 3-44 v/v, or 2*73%, the and above that limit it does not occur at all. F. H. L. - ~- Reactions of Some Common Phenols. G. Deniges. (Bull. Soc. Pharm. Bordeaux, 1898, 241 ; through Ann, de Chim. Anal., 1898, iii., 381, 382.) Reactions with Mercuric Szdphate. --Five centigrammes of the polyphenol are dissolved in 2 C.C. of water, 3 C.C. of the author's mercuric reagent (ANALYST, xxiii., 216) added, and the whole shaken. h lemon-yellQw precipitate is obtained .. . ... . . . Pyrogallol. No precipitate. The liquid becomes yellow, changing to No precipitate. A yellowish-white ,, 9 , ... ... . . - Phloroglucinol. yellowish-red and to reddish-brown . . . ... . . . Pyrocatechin. H ydroquinone. The liquid remains colourless, or has a slight greenish-yellow tint . . . ... I.. ... On boiling becomes yellowish-red . . . . _ . ... On boiling no perceptible change . . . ... ... After immersion of the tube in cold water and .prolonged standing a yellowish precipitate ... ... Reactions with Soda.-From 15 to 20 centigrammes of the substance are dis- solved in 3 to 4 c . ~ . of alcohol, 1 c . ~ . of a solution of soda allowed to flow down the side of the tube and the zone of contact observed.THE ANALYST. 39 (a), A coloured zone is produced immediately.surmounted by a green ring. surmounted by a white ring. On shaking the liquid On shaking the liquid Red { becomes green ... ... ... ... Hydroquinone. ... becoiiies brown ... ... ... Pyrogallol. Yellow, with a yellow coloration of the supernatant alcohol ( b ) No immediate coloration, but after some time a green ring Pyrocatechol. White ... a. ... ... ... ... Phloroglucinol. appears ... ... ... ... ... ... Resorcin. (Gy. ANALYST, xxi., 295.) Humble-Bees' Wax. E. E. Sundvik. C. A. M. (Zeits. Ph?~sio$. Chenz., 1898, xxvi., 56 ; through Clzem. Zeit. li'ep., 1898, 321.)-From 130 grammes of comb the author obtained, by extraction with ether or chloroform, about 30 grammes of crude wax, melting between 35" and 40" C. The odour was pleasant, resembling honey, and not at all rancid.The wax bleached almost perfectly when exposed to daylight in thin layers ; but became very rancid in smell. Treated with weak caustic potash, and crystallized six or seven times from alcohol, it melted at 69"-70"; finally it melted at 74" or 75" C. The intermediate product possessed the sticky nature of ordinary beeswax ; the purest did not. The crystals form fine, soft, woolly needles. Even in the cold it is more or less soluble in the regular fat-solvents. Its empirical formula is C,,H7,0. Heated to 150" or 160" with benzoic anhydride, it gives a substance easily soluble in hot .or cold alcohol, which, after several recrystallizations, melts at 55" C. F. H. L. (&dI. de $'Ass. Belge, 1898, xii., 143-151.)-This paper gives an account of the authors' investpigation on the different methods of determining pentoses, and describes various modifica- tions which they have adopted.For the estimation of pentoses, after conversion into furfural, two methods are employed : that of Tollens, in which the furfural is precipitated by means of phenyl- hydrazine ; and that of Councler, in which phloroglucol is used as the precipitant. Several chemists have been unable to obtain satisfactory results by the second method, and hence the precipitation of the pentoses as hydrazones is the one in general use : The Estimation of Pentoses. A. Grbgoire and E. Carpiaux. C,H,O,+ C,H,NH.NH, = C,H,NH.NH.C,H,O + H,O. The hydrazone was formerly determined volumetrically (Tollens and Giinther) or gravimetrically (Tollens and Chalmot), but Flint and Tollens' recent researches (Landzu.Vers. Stat., dii., 395) have shown that in the volumetric method the distil- lation of the substance with hydrochloric acid yields small quantities of substances (acetone, etc.), which combine with the phenylhydrazine, although they do not form an insoluble compound, and hence the results are too high. In the gravimetric method the distillate containing the furfural is diluted to 400 C.C. with hydrochloric acid, neutralized with sodium carbonate, slightly acidified with acetic acid, the furfural precipitated with an acetic acid solution of phenyl- hydrazine, the solution brought to 500 c.c., and, after being mechanically stirred for thirty minutes, the precipitate collected on a filter of glass wool, washed with water,40 THE ANALYST.dried in a current of air, and weighed. The weight of the hydrazone multiplied by 0-538 gives the furfural. The authors find that there is a slight source of error in this method, owing to the hydrazone dissolving to a slight extent in the water required to wash the pre- cipitate. To obviate this they have devised a gas-volumetric process, in which the nitrogen in the phenylhydrazine is determined before and after the precipitation, and the difference calculated into the amount taken up by the furfural. The original phenylhydrazine is decomposed by means of copper sulphate : but this is not possible in the presence of sodium chloride, as in the filtrate from the precipitated hydrazone, unless the process is modified.Pheny lhydrazine acetate, like ammonium acetate, decomposes on boiling, but the authors' experiments show that by making the liquid strongly acid with hydrochloric acid, the phenylhydrazine can be boiled without alteration. In the gas-volumetric process finally adopted the nitrogen in the phenylhydrazine reagent was determined in the following manner : From 4 to 4.5 grammes' were dissolved in 250 c c. of water, 25 C.C. of the solution were mixed with 20 C.C. of con- centrated hydrochloric acid, boiled for several minutes to remove all air, and intro- duced while hot into a Schloesing's (nitric acid) apparatus containing 25 C.C. of zt 20 per cent. solution of copper sulphate and several C.C. of hydrochloric acid, from both of which all air had been expelled by boiling.The reaction took place instan- taneously, in accordance with the equation : The liberated nitrogen was eollected and measured in the usual manner, corrections made for the vapour tension of water and chlorbenzene at the temperature of obser- vation, and the calculated weight of nitrogen multiplied by 3.857. Thus in a typical case 94.8 C.C. of gas were obtained at a temperature of 19" C. and a pressure of 748 mm., which corrected for temperature, pressure, tension of the water vapour, and chlorbenzene vapour was 721 m.m., corresponding with 88.51 per cent, of the phenyl- hydrazine taken. For the precipitation of the furfural, 81.5 grammes of sodium chloride (the quantity corresponding to the amount of hydrochloric acid which distils over in the estimation of pentoses) were dissolved in about 400 C.C.of water, 2 drops of acetic acid added, and a quantity of furfural not exceeding 0.6 gramme. After the addition of an aqueous solution of phenylhydrazine (4 or 4.5 grammes in 250 c.c.), the liquid was made up to 500 c.c., and shaken for at least an hour in a Witt agitator. The filtrate was at once mixed with hydrochloric acid, which was found to prevent the decomposition of phenylhydrsaine acetate. It was then boiled to expel the air, and 200 C.C. containing 20 C.C. of hydrochloric acid were introduced into Schloesing's apparatus, and the nitrogen determined as before and deducted from the amount found in the first determination. The result multiplied by the factor 3,429 gave the amount of furfural. In seven analyses of furfural by this method the percentages found varied from 99.4 t o 102.4 per cent., the mean being 100.5 per cent.C,H,NH.NH, + 2CuS0, = H,SO, + C,H, + N, + Cu,SO,, C,H,N.NH, + 4CuS0, + HCl= 2H2S0, + C,H,Cl + ~CU,SO, + N,. C . A.M.THE ANALYST. ing matters. 41 alone. Non-reducible colouring matters. A Method of Analysing Natural and Artiflcial Organic Colouring Matters. A. R. Rota. I. Identification of Imhidual Colouriiag Mutters. - I n this paper €he author draws up a scheme of analysis based upon the recent views of Nietzki, Witt, Armstrong, and others, as to the relationship which exists between the constitution and colour of these substances. Regarding organic colouring matters as quinone derivatives (Armstrong, Nietski), those which are based upon mono- and di- amido-quinone are reducible by stannous chloride; while those which are regarded as derivatives of a quinone, in which an oxygen atom is replaced by a di-valent hydrocarbon group in the quinone ring, are not reducible, Thus, if O = R = 0 represent an ortho- or para- quinone, the nitroso- axo- and imido- quinone colour derivatives are reducible : (Chem.Zeit., 1898, 437-442.) O = R = N - or - N = R = N - oximido-quinone di-imido-quinone, but not such derivatives as oxyquinone- and triphenyl- methane Golouring matters : O = R = C = and - N = R = C = oxycarbo-quinone imido-carbo-quinone. The reduced colouring matters can be subdivided into two groups, according as to whether the colour is restored on oxidation with ferric chloride or atmospheric oxygen ; and the unreduced colouring matters can also be subdivided according to their behaviour on treatment with caustic potash.Four main groups are thus obtained, as shown in the subjoined scheme. The aqueous or alcoholic solution of the substance is diluted to about 1 : 10,000, and 5 C.C. treated with 4 to 5 drops of concentrated hydrochloric acid and about the same quantity of a 10 per cent. solution of stannous chloride. The mixture is shaken, and, if necessary, warmed to the boiling point. If no decolorization. occurs, the solution of the colouring matter should be again tested with stannous chloride after still further dilution, A. ClussiJicatioiz of Organic Colozcri?zg Matters. CLASS I. Nitro-, nitroso-, and azo- colouring matters, i n c l u d i n g azoxy- and hydrazo- colours.Indogenide- a n d imido- quinone colour- ing matters. CLASS IV. Aniido-derivatives of di- and tri- phenylme- Non-amide dipheiiyl- thane, auramines, acri- methane colouring mat- dines, quinolines, and ters, oxy-ketone colour- colour deriratilTes of ing matters (most of the thiobenzenil. I natural organic colour- ing matters).42 THE ANALYST. The individual colouring matters in the four main groups may often be identified by reference to one of the published tables of their physical, chemical, and tinctorial properties, which, however, only describe a part of the dyes now met with in commerce, A differ- entiation can often be made in the case of halogen derivatives of similar phthaleins, for instance, by determining the halogen after igniting the colouring matter with lime.The detection of sulphur by fusing the dye with potassium nitrate, and testing the melt for sulphuric acid, often enables one to differentiate between two substances, as, for instance, between the thiazines and oxazines. When the colouring matter was reduced by stannous chloride, the decomposition product may be further examined after removing the tin with sulphuretted hydrogen. Picric acid, for example, gives the colourless tri-amido-phenol, which on treatment with ferric chloride gives the blue amido-di-imido-phenol. The azo colouring matters give on reduction with stannous chloride at least two primary amines in accordance with the equation : I n doubtful cases resort must be made to the spectroscope. R - N = N - R, + 2H2 = R - NH, + R - NH,.These amines can often be separated by means of ether. The reduced solution, from which the tin has been removed by means of sulphuretted hydrogen, is treated with caustic potash and the liquid shaken with ether, which dissolves the non-sulphonated arnine, and leaves the sulphonated amine in the aqueous layer. The latter can be identified by the characteristic azo-compound which it forms with certain diazo- derivatives. Sulphanilic acid, for instance, obtained by the reduction of naphthol orange, combines with diazo-benzidine-chloride to form a yellow tetrazo-colouring matter. Naphthionic acid yields Congo-red ; and certain oxy-sulphonated amines, such as C,,H,-OH(8) Since the NH, group resulting from the azo groups must be in the para-position to another amido group in the radicle, a para-diamine is produced, and this can be easily recognised by the thiazin reaction (treatment of the solution freed from tin with hydrochloric acid and ferric chloride in the presence of sulphuretted hydrogen).A para-diamine is also obtained from those colouring matters which contain not the ctmido group, but two diazo groups, since the middle radicle contains the two azo groups in the para-position. Thus, Sudan 111. (A), on reduction with stannous chloride, gives : /NH2(2) \ SO,H(6), give a violet colour (diamine black R (C), etc.). By this reaction it is possible in the absence of an amido substance to determine A scheme of the characteristics of members of the four groups is shown in the whether a mono-azo or a diazo colouring matter is present.following tables :THE ANALYST. 43 water. Wool and silk dyed directly, but not cotton. The HC1. With HC1+ SnClz par- in presence of‘ tially reduced, giving red KOH. nitro-amido derivatives (nitra- mines) or nitro-phenols turn- aqueous solution shows ten- dency to decolorization with soluble in ether NITRO-PHENOLS. In- B. Class I.-Redwecl by HCI +- SnCl, awl not Reoxidixuble. / Noit - sidphonated. Sol- //O Victoria \H yellow. Sulphonded. Insoluble Naphthol in ether. yellow. presence of acetic acid. uble in ether in O=R=N NITRO-COLOURING MATTERS : ,NY?~A~!S. Soluble in ether in presence -N,R=N(O e.g., R - NO.,. OH Aurantia. Colourless solu- tion. Yields nothing t o ACID COLOUR- ING MATTERS. acetic acid.‘ a t e d. E x - OXYAZO-COLOUR- I n d i r e c t f o r Diamond yellow t r a c t e d b y ING MATTERS cotton wool.ether f r o rn w I T H C A R- Direct for cotton Chrysamine, dilute solution BOXYL GROUP. wool. in acetic acid. .N o N - A M I D O I n d i r e c t f o r Bordeaux B SuZp honated. COMPOUNDS. cotton wool. (4 - Not extracted Unaltered by Direct for cotton Azo-blue (A). solution i n \ A x I D o COM- I n d i r e c t f o r Solid yellow dilute acetic 1 P o u N D s. I cotton wool. by ether from( HNO,. N (P). I I wool. AZO-COLOURING MATTERS : Their aqueous so- l u t i o n decom- posed with KOH a n d extracted with ether, gives an ethereal ex- tract with the annexed charac- R -N=N - R. 1 acid. \ ( &poged by Direct for cotton Congo red (A). c wool. Class II,-Eerlucecl by HCl+ SILCI, awl Beoxidixable.0 x Y A z I N E s (no N/ ”>’ T H I A Z I N E S (sul- N/’R1\S tion is coloured readily or colourless, and ’ by \R = N I acid. I phur). =N- - The ethereal soh- ,The solution yields the ori- 1 in the cold. ginal colour to 5 per cent. acetic I Nile blue A (13). I NR / Methylene blue. i BASIC COLOURING MATTERS. Fixed on wool in dkaline bath. The coloured solu- tion is reduced but slowly and i n c o m p l e t e l y , I even on warming, j and with the ad- dition of much [ SnCl,+HCl. ’INDULINES. Blue colour with cone. H,SO,. Blue on dilution. SAFRANINES. Green c o l o u r w i t h H,SO,. On dilu- tion blue, then violet. Induline. Soluble in alcohol. Safranine T. Extra (A).Coloured. Does not Blue colouringmat- yield the colour ters changed by INDOPHENOLS. HC1 on warming.ING MATTERS. i Red or blue colour- to acetic acid. NEUTRAL COLOUR- ing matters. Un- With HNO, yield altered by HCl. INDoGENIDES. - - fibres in bath. 1 isatin. Non - sulphonated. Soluble in ether oXAZONES. in presence of acetic acid. acid. MATTERS. Fixed on wool acid bath. Class III.- Colozcriizn The ethereal so- lution is co- l o u r l e s s o r coloured. The c o l o u r i s y i e l d e d t o 5 per cent. acetic acid. BASIC COLOUR- ING MATTERS. Fixed on wool in alkaline bath (NH,). '"I stances* Matters Yzot '<; = 0 Indophenol. I1 Fluorescent blue, orcein. dR\0 \"Lo - SULPHONATED IN- DOGENIDES, Indigo carmine. SULPHONATED Thiocarmine R THIAZINES. (C>* Not reduced by -I SnC1,fHCl. SULPHONATED IN- DULINES. Containing t h Soluble nigrosin.Iqnido- quinoq~ Carbon Chrorrzophore - N = R = C = . Colourless, non-fluorescent, solution. Yellow colour y i ~ l ? c Y ~ ~ \ acetic acid non - fluorescent. aqueous solution is decolorized by KOH and decomposed by HC1. Colourless, ethereal solution. Green fluorescence. Aqueous solution pre- cipitated by KOH, hardly altered by 1 yielded to acetic acid - reddish- violet, blue, and green without fluo- decolorized on warming with KOH, HC1. Turns red with HNO,. Colourless, or coloured ethereal solu- tion. Non - fluorescent. Colour rescence. Aqueous solution usually and coloured yellow by HC1 (ex- cepting fuchsin). Ethereal solution colourless and non-fluorescent. Acetic acid coloured rose and fluoresces. Aqueous solution ,decolorized with KOH. The ).AURAMINES. I I (non-sulphon- ated)' I PYRONINES (coloured altered bv HC1./R\ \R/ -C-N /R C-R \R=N- R -c/ ' 0 \ R L ~ _ - ey.9 Auramine 0 (B). Phosphine. Fuchsine. Pyronine (G). Rhomamine S (BY). The coloured ethereal solution does not yield its colour to acetic acid. Quinoline yel- \ R = N Z uble in alco- low A (sol- hol) . NEUTRAL COLOURING MATTERS. non-fluorescent, and Insoluble in water. Soluble in 1 unaltered by aqueous alcohol. Ethereal solu- tion colour- less. Yields n o t h i n g t o acetic acid. ACID COLOUR- ING MATTERS. Soluble in water. Fixed on wool in acid bath (HC1). L \ acids and alkaiies. I in water. and alkalies. Yellow colouring matters. No fluorescence Reddish-violet, blue, or green colouring matters. Usually decolorized by KOH, little changed by HC1. Red or violet colouring matters.Soluble tated by HCl. Changed but little, or Unaltered by aqueous acids 1" I ITHIAzoLEs* in water with fluorescence. Precipi-1 S not at all, by KOH. colouring matters. Aqueous solution f fluorescent. Brownish - yellow or orange l U L P H 0 N ATED Q U I N 0 N - E - PHTHALONES. U L P H 0 N ATED FUCHSINXS. ULPHONATED RHODAMINES. - C = N I I S - R Quinoline yel- u b l e i n water). F u c l i s i n e S low A (sol- (B). Violamine R (MI. Primdin (B) .THE ANALYST. 45 :lass IV.--Colourinq Matters not Reduced by Snc'l, -I- HCI. Coiztaiizing the 0x9-qasinone Carbon C hromop hore 0 = R = C = . C-R \R, = 0 Remains unaltered. 15 2 -8 Not directly fixed on 2 ~1 r;l wool. Most of them insoluble in water. a g' PHENYL - METHANE without f l u o r e a - COLOURING MAT- cence.i Fixed directly on wool. $ Most of them soluble in water and alcohoL Fluorescence. NON-AMIDO TRI- Soluble in alcohol z s 0 OXY-KETONE d m COLOURING MATTERS. Most of them insoluble :in water, and indirect for fibres . D 7s' s o 1 v e s with yellow or reddish- y e l l o w colour. 15 O N O K E - TONES. -2H D i s s o l v e s QO with r e d , 2% r e d d i s h - a violet, vio- gz letgreen, or -c is blue colour. 43 DIKETONES u (quinones j. I /I{ \R i * Inclined to de- ~3 colorization, 2 X 3 "O warming(with $ decomposi- 2 2 tion). especially on ,-B E N z 0 P H E - co I .r( The free colour-5 for fibres. Colouring mat- ter remains in d i r e c t l y on wool. Auriii. Eosin. Alizarin yel- low A (B). Quercetin. Alizarin. co<$Jco Sulp hona t e d alizarin (ali- zarin-red).11. The Separation of Co~ozcri?zq Matters in a Mixture.-It is sometimes possible to effect a separation by treating the mixture with water or alcohol at the ordinary temperature, or with the aid of heat ; but as a rule extraction with ether or by fixing the dye on wool or other fibre is the most promising method. The behaviour of ether and wool is very similar, both extracting the free colouring matters, but not their salts. At the same time, not all colours soluble in ether can be fixed upon wool. Extraction with Ether.-It is possible to separate basic from acid colouring matters by adding potash to a dilute aqueous solution of the dye and shaking with ether, when the free bases dissolve in the ether, leaving the acids in the aqueous layer.The details of the process are as follow : 100 C.C. of the aqueous solution of the colouring matter are decomposed with 1 C.C. of a 20 per cent. solution of potash, and shaken with three times the volume of ether. The aqueous alkaline solution of the acid colouring matter is neutralized with acetic acid and examined subsequently. The ethereal solution of the colour base is washed with faintly alkaline water, and then shaken with one-third of its volume of 5 per cent. acetic acid. The acid layer is separated, and on evaporation on the water-bath leaves the colouring matter as a,46 THE ANALYST. residue. In those cases in which the colour remains in the ether, the latter is evaporated. In the presence of potash some few acid or neutral colouring matters are also extracted by the ether, as, for example, quinoline yellow, indophenol blue (soluble in alcohol), the various sudans, etc.These are all insoluble in water, but soluble in alcohol. I n the extraction of the colour bases different alkalies have different liberating powers. Thus, safranine requires caustic potash, while for fuchsine ordinary ammonia 1s sufficient ; others, again, such as the indulines, oxyazines and acridines, have their colour bases set free by very dilute ammonia; and others, such as chrysoidine, Bismarck brown, rhodamine S(By), Victoria blue, etc., dissociate in dilute aqueous solution. Thus, separation can often be made by successively shaking the aqueous solution with ether, first alone, then together with 1 per cent. ammonia, then with concentrated ammonia, and finally with 20 per cent.potash. A further separation of the bases taken up by the ether can sometimes be effected by shaking the ethereal solution with an equal volume of water, some being taken up by the water, others remaining in the ether. In this way it is possible to separate acridine yellow from the very similar phosphine. The colour bases remainingin the ether differ in their behaviour towards 5 per cent. acetic acid, some combining with it, others remaining unaltered. The acid colouring matters not extracted by ether from an alkaline aqueous solution can be separated by methods similar to those used with the colour bases. By successive extractions with ether, they can be separated into three groups: (1) those extracted by ether in the presence of acetic acid of 1 per cent.strength ; (2) those soluble in ether in the presence of hydrochloric or sulphuric acid; and (3) those insoluble in ether. Erythrosin can thus be separated from roccellin and from Bordeaux B, and direct yellow (A) from Congo brown R (A) and from Congo red (A). By treating the ethereal solutims with water and dilute ammonia, as in the case of the basic colouring matters, a further separation can often be made, as, for instance, picric acid from Martius yellow. Separation by means of Wool.-When a separation cannot be made with. ether, it is often possible by means of wool. An aqueous solution of the colouring matter (1 : 1,000) is rendered faintly alkaline by the addition of four or five drops of ammonia per 100 c.c., some wool added, and the liquid heated to boiling with constant stirring.This is repeated with fresh supplies of wool so long as the fibres are dyed. The wool is washed with boiling ammoniacal water, then with pure water, and extracted with 5 per cent. hot acetic acid. On evaporating this extract on the water-bath, the basic colouring matters are left, and can then be further separated. The use of wool is more effective in the separation of acid colouring matfers, some of which are directly fixed by it. A 0.1 per cent. solution of the colour mixture is acidified with hydrochloric acid (three to four drops per 100 c.c.), brought to the boil, and wool immersed for from three to five minutes with continual stirring. This treatment is repeated as with the basic colours.The dyed wool is washed with acidified water, and then with pure water, and the colour extracted with 5 per cent. ammonia. By boiling the liquid until the ammonia is expelled, the direct colours are obtained in neutral solution. Since Borne of the indirect colours are taken up toTHE ANALYST. 47 a slight extent by the wool fibre, this solution should also be treated with the wool in order to effect complete separation. I n this way the following colours can be separated from each other : Direct. Indirect.{ anocyanin. {Cochineal. (Saffron. Bordeaux B (A). Biebrich scarlet.JAcid yellow (A). The direct colours have a great difference in their affinity for wool, and with some it is dyed readily in a strongly acid solution (e.y., those with oxysulpho- groups), while others, of both acid and basic character, also dye in a neutral solution.The following colouring matters can thus be separated : Fixed in neutral bath. Alkali violet (B). Acid violet 4BN. (Orseille ,, acid ,, {Ponceau 6RB (A).{New coccine (A). \Bordeaux B (M). By-using a strongly acid solution (1 C.C. HC1 to 200 c.c.) the following separations ,? slightly 9 > {Orange G (A). {Methyl orange. can be made : Fixed in strongly acid bath. Bordeaux S (A). Bordeaux B (A). When a separation of the constituents of a mixture cannot be effected by means I t has the property of fixing some of the direct of wool, cotton-wool must be tried. dyes for wool, leaving others in the bath. Thus : Direct for cotton-wool. Carbazol (B). Cotton yellow R (B). Indirect ,, ,, (Diamond yellow R (By).{ Phloxin B (B). With cotton also some of the dyes are more readily fixed than others, especially under varying conditions of the acidity and concentration of the bath. Thus, in slightly acid bath (HC1) brilliant Congo (A) is readily fixed, but brilliant yellow (A) only with difficulty. If none of these means have effected a separation, other solvents, such as petroleum spirit, arnylic alcohol, chloroform, etc., should be tried. With petroleum spirit, for example, eosin can be separated from Martius yellow. C. A. M. Use of Basic Lead Acetate in the Polarimetry of Sugar Solutions. Prinsen- Geerligs. (D. Zzdcerind, 1898, xxiii., 1753 ; through Chem. Zeit. Rej?., 1898, 320.) -Although basic lead acetate does not precipitate pure lmdose, yet from impure solutions, and notably such as contain much saline matter, it carries down more or less sugar with it. On preparing artificial liquids from honey and common salt to imitate natural juices (13.44 per cent.of invert sugar and 7-68 per cent. of sodium chloride), and adding increasing proportions of basic lead acetate, the amount of laevulose precipitated varied between 343 and 23.14 per cent., thus causing a corre- sponding increment in the dextro-rotatory power of the solution. When sufficient of the reagent is introduced to decompose all the salt's present in the juice, further additions have no effect on the sugar. As lead nitrate, normal acetate, bone-charcoal, and zinc dust are all unsatisfactory, it is necessary to employ basic acetate ; and in order to obtain comparable results, the author suggests that the quantity of lead required to render molasses fit for optical examination shall be determined, and the same quantity used for all other kinds of syrup and crude sugars.The precipitated48 THE ANALYST. lzevulose also contains glucose, but the proportion of the latter never exceeds 25 per cent. of the total sugar thrown down. F. H. L. The Estimation of Indigo on Fabrics. A. Binz and F. Rung. (Xeit. angezo. Chem., 1898, 904-905.)-Renard (Bull. Xoc. Chim., xlvii., 41, 1887) proposes to heat a weighed portion of the fabric with a measured quantity of hydrosulphite solution, and determine the indigo white in an aliquot portion of this, His niethod is objection- able, since indigo white is obstinately retained by the tissue.The method of extracting the fabric with aniline in a Soxhlet apparatus, as proposed by Honig (Zeit. any. Chenz., 1889, ZSO), is much simpler. As, however, boiling aniline exercises a destructive action on indigotin, glacial acetic acid, as proposed by Brylinski (Rev. gBn6.p.. mat. color., 1898, 52), forms a better solvent, The paper contains an account of the authors' comparative experiments with Brylinski's method slightly altered, and with a modification of the hydrosulphite method. In the latter the fabric was treated with the hydrosulphite solution on the water-bath until completely decolorized, and the indigo-white removed from the tissue by repeated washing out with hot water, of which from 2.5 to 3 litres were required to remove only a few decigrammes of the dye.The whole of the solution of indigo white thus obtained was oxidized by means of a current of air, and the indigo collected on a tared filter-paper, dried and weighed. In the experiments on the glacial acetic acid method a suitable quantity (10 grammes) of dyed cotton was heated for three or four hours over a naked flame with 150 C.C. of glacial acetic acid, and then poured into 300 c.c, of water. Instead of now filteringoff with a suction-pump, as Brylinski directs, the authors found it preferable to add 150 C.C. of ether. The whole of the indigotin remained in suspen- sion in the ethereal layer, and this was separated from the diluted acetic acid by means of a separatory funnel. The former was filtered off, the precipitate washed with alcohol and ether, and dried at 110" C.The results obtained by the acetic acid method were somewhat higher than those of the hydrosulphite process, and this the authors considered might be due to over-reduction by the hydrosulphite, or to an acetyl derivative of cellulose dissolving in the acetic acid. Brylinski states that the latter body is soluble in ether, and the authors found that this was the case ; for, on extracting two equal weights of a dyed fabric, to one of which about forty times its weight of bleached cotton-wool had been added, the amounts of indigotin obtained were practically the same. C. A. N. The Determination of Sulphur in Asphalt. E. H. Hodgson. {Jozir. Amer. Cl~om. Xoc., vol. xx. 1113, pp. 882-889.)-Various samples were examined by the methods of Carius (heating with strong nitric acid in sealed tubes), Peckham (defla- gration), Eschka (ignition with calcined magnesia), and by fusion with sodium peroxide.From the results the sealed tube method appears the most accurate, but is a lengthy operation, and the tubes are liable to explode. Of the others, that of Eschka is probably the best, giving good results and requiring least time and attention. c. s.THE ANALYST. 49 Use of Persulphates to Detect Albumin in Urine. C. Strzyowski. (Schweiz. Wochs. Chem., 1898 [48] ; through Deutsche Chem. Zeit., 1899, xiv., 2.)-A 10 per cent. aqueous solution of potassium, sodium, or preferably ammonium persulphate, pre- cipitates albumin from either acid or alkaline urine, and does not throw down peptones or urates.By means of a pipette the reagent is brought underneath a layer of the suspected urine contained in a test-tube, when even in dilutions of 1: 100,000 a grayish-white turbidity is produced at the line of contact. In presence of bile pigments the colour is bright green. F. H. L. Estimation of Chlorides in Urine, Wine, Beer, and Cider. Loubiou. (Rep. Pharm., 1898 [3], x., 493; through Chem. Zeit. Rep., 1898, 319.)-Lead peroxide oxidizes in the cold those constituents of urine which act on silver nitrate, and decolorizes it sufficiently to enable potassium chromate to be used as an indicator in the titration of chlorides. 20 C.C. are shaken with 2 or 3 grarnmes of the peroxide and filtered; 10 C.C. of the filtrate are mixed with 5 drops of saturated potassium chromate, diluted to 50 c.c., and titrated as usual.Similarly, employing Blarez’s process, 50 C.C. of white or red wine (beer, cider, or vinegar) are treated with 3 C.C. of chromate, 50 granimes of salt, 100 C.C. of water, and 5 grammes of lead peroxide; the whole is shaken, filtered, and an aliquot portion titrated. F. H. L. Separation of Albumoses from Peptones. P. Muller. (Zeits. Shysiol. Chem. , 1898, xxvi., 48 ; through Clzern. Zeit. Bcp., 1898, 320.)-After experiments with the salts of various heavy metals, and especially with uranium acetate, the author prefers ferric hydrate for this purpose. The liquid to be treated is mixed with an equal volume of 30 per cept. ferric chloride solution, and alkali is added till it is only just acid. The precipitate is removed, two or three pinches of zinc carbonate are thrown into the filtrate, which is shaken thoroughly and again filtered.It will be clear, colourless, and free from albumoses, giving no turbidity (or only a very slight one visible against a dark background) when saturated with ammonium sulphate. The method has proved successful in all cases where it was tried except with Witte’s peptone, which involved a concentration of the filtrate to one-fourth or one-fifth of its volume, followed by a second treatment with a few drops of ferric chloride and zinc carbonate as before. 3’. H. L. Sicilian Sumach and its Adulterants. F. Andreasch. (Gerber, 1898 ; through &?its. nngezo. Clzem., 1898, 1154.)-True sumach is the product of Rhus coriarin, an Arabian plant ; but it is blended with the leaves of the Sommacco fimeneddu, which contain less tannin.Inferior specimens are mixed with stalk, earth, sand, and already extracted sumach. As adulterants there are added leaves of the carobbe, OC CistzLs salz;ifolius (very frequently in Sicily), of the fig, vine, of Ailanthzcs gla~~duloscc, Pistacia Zentisczu (Stinco sondro, Lentisco), and of Turnarix Africana (Bruco, albero di Giuda) : the two latter being the most common. The amount of tannin and non- tannin in sumach and its chief adulterants is shown in the annexed table. The average proportion of tannin in pure sumach may be taken at 23 or 24, seldom falling50 THE ANALYST. below 22 : a yield of under 20 per cent. points either to the presence of other parts of the plant or to sophistication.Large additions of stalk, etc., can usually be detected by the eye, if not by examination of the aqueous extract ; for the bulk of the red colouring matter in the woody fibre passes into solution, and on acidification with acetic acid yields a weak but distinct red tint. Tannins. Non - tannins. Silician sumach. . . . 21--27-5 per cent. . . . 16-22 per cent. Pist acia ... ... 13-17 ,, ... 20-26.6 ,, Tamarix ... ... 8.3-9 7 ,, ... 23-26-5 ,, Ailanthus . . . ... 10 ,) ... 17-5 ,, When a little formaldehyde is dropped into a neutral decoction of pistacia, a pale-yellow precipitate is produced. Even if the material is chiefly genuine sumach, a yellowish-coloured cloud forms, which appears as a precipitate in time, but only settles after several days. The deposit is gelatinous and coheres on the filter, so that it can scarcely be washed. The substance is insoluble in cold water ; but it does not represent a, quantitative separation of the pistacia. If the test be carried out on very old samples of sumach, which perhaps have fermented, or if much tamarix be present, the formalin may produce a precipitate even in the absence of pistacia; but the latter cannot be mistaken for the real deposit : it is only small in amount, never gelatinous, and settles in twelve hours. When solid potassium cyanide, or its strong solution, is stirred up with a decoc- tion of tamarix, or sumach adulterated with tamarix, a flocculent dark-yellow pre- cipitate is formed which settles rapidly. Pure sumach gives no deposit or a mere trace, and the reaction is characteristic of tamarix alone among the possible adul- terants. The reagents in both tests must be pure, and the solution examined should be perfectly clear, and must not exceed industrial strength, viz.,. about 0.75 gramme of tannin per 100 C.C. F. H. L. Estimation of Oil of Bergamot. A. Soldaini and C. Berte. (BOLL. chim. farm., 1898, xxxvii., 577 ; through Chenz. Zeit. Rep., 1898, 311.)-The usual adul- terants added to bergamot oil are turpentine and (or) lemon oil. To detect them, 15 C.C. of the sample should be distilled at a pressure of 20 or 30 mrn. till 5 C.C. have passed over, and the opticity of the oil, the distillate, and the residue determined. The annexed table indicates the influence of both or either of the impurities men- t ioned : Temperature. Oil. Residue. Dis tillste. Pure bergamot oil ... Y . ... 14" C. +14" 50' -0" 56" +41" 2 0 + 5% of lemon oil . . . ... 14" C. +17" 11' +3" 20' +42" 28' +2*5% of turpentine and 2.5% of lemon oil ... ... 13.5" C. + 14" 55' + 2" 40' + 40" 20' +5% of turpentine ... ... 14" C. +12" 36' -0" + 35" 28' F. a. L.

ISSN:0003-2654    

DOI:10.1039/AN8992400037

出版商:RSC    

年代:1899

数据来源: RSC

摘要:

THE ANALYST. 51 INORGANIC ANALYSIS. Bacterial Detection of Arsenic. F. Abba. (CerttralbZ. Bakteriol., 1898, [2], iv., 806 ; through Chem. Zeit. Rep., 1898, 310.)-Gosio has already shown that when Penicillium brevicazde is cultivated in presence of arsenic a garlic-like odour is produced. The present author finds that this process is not only simpler than ohemical methods of detecting arsenic, but, after investigating fifty other substances, that it is quite characteristic. It is also more delicate, for a piece of Indian fur 1 square millimetre in area gave the reaction, whereas even 5 square centimetres did not show the Marsh test. The material to be examined is placed in sliced potato, sterilized at 115" for twenty minutes, inoculated with 0.5 C.C. of sterilized water containing spores of the P.brevicaule in suspension, and cultivated either at 37" or at ordinary temperatures. Fresh cultures of the penicilliurn need only be prepared once a year. 3'. H. L. Colorimetric Estimation of Iron in Water. (Chem, Zeit., 1898, xxii., 1086.)-Lunge's colorimetric process for determining traces of iron in aluminium sulphate is very suitable for the examination of water. Instead of matching the colour of the aqueous solutions as in the usual method, each is shaken up with a measured quantity of ether, and after the layers of ether have been adjusted to the game length, the colour comparison is made in these. If the water under examination contains much organic matter an error may be introduced ; in this case the samples must first be evaporated in platinum, ignited, fused with sodium carbonate, and the melt dissobed in hydrochloric acid.A. Seyda. F. H. L. Remarks on the Determination of Zinc and Manganese as Sulphide. E. Murmann. (1CIonats7zefte fiir Chernie, xix., 404.)-On account of the difficulty of filtration, the determination of zinc or of manganese as sulphide is rarely resorted to, though the method is capable of yielding very accurate results. The author over- comes this drawback by adding mercuric chloride to the solution before precipitation. The precipitated mercuric sulphide enables the finely divided zinc or manganese sulphide to be filtered off and washed without difficulty, whilst in the subsequent ignition of the precipitate the mercuric sulphide is completely expelled. The author has also devised a new form of crucible specially adapted for the ignition of such precipitates in ti current of hydrogen gas.Its construction is shown in the accompanying figure. The crucible a has a perforated bottom b, to which is aftached a tube c, which can be either straight or bent at right angles. ,4 perforated plate fits into the bottom, and between the perforated bottom and the perforated plate is a plug of asbestos as used in the Gooch crucible. The mouth of the crucible is covered by an ordinary crucible lid. The precipitate is filtered off and also dried and ignited in the crucible, whilst by means of the tube at the bottom a current of hydrogen can be passed through it during the ignition. The %T crucible can, of course, be used for other similar purposes.H. H. B.-S.52 THE ANALYST. Estimation of Manganese aa Phosphate. E. A. Gooch and M. Austin. (Zeits. anorg. Chem., 1898, x+iii., 339.)-In this process the metal is thrown down as trimanganese orthophosphate, the precipitate converted into ammonium manganese orthophosphate, and finally weighed as manganese pyrophosphate. Its accuracy, therefore, depends upon the rapidity and completeness with which the Mn,P,O, is changed into MnNH,PO,, and the degree of insolubility of the latter, which, a s Fresenius and Munroe have shown, is considerably affected by the presence of ammonium chloride. The present authors have investigated the method under various conditions, ultimately finding that a very large excess of ammonium chloride (200 molecules of NH,C1 to 1 of MnNH,PO, in 100 or 200 c;c.of liquid) is absolutely indispensable to a quantitative conversion of the original precipitate into the double phosphate, and, moreover, that MnNH,PO, is not appreciably dissolved by ammonium chloride solution, provided excess of the soluble phosphate employed as a precipitant is always present. Details for the successful operation of the process are as follows : The original faintly acid liquid (containing. not more than 0-2 gramme of metallic manganese) is mixed either in a platinum or a glass vessel with 20 grammes of solid ammonium- chloride, 5 or 10 C.C. of a cold-saturated solution of microcosmic salt, and diluted to 200 C.C. ; dilute ammonia is then added in the cold drop by drop until it forms a slight excess. The whole is heated till the precipitate becomes crystalline, aIlowed to cool for half an hour, filtered quickly through a Gooch crucible with the aid of a pump, and washed (preferably) with very weak ammonia.The filtrate is always quite free from manganese, and if the precipitate retains traces of ammonium chloride, this can only lead to the formation of equally minute quantities of manganese chloride. It is better to arrange for a precipitate weighing about 0-4 gramme ; but even with smaller amounts the final error will average not more than 1 mgm. of manganese. I?. H. L. The Determination of Chromium Oxide in Algerian Phosphates. G. Schiiler. (Zeits. angew. Chem., 1898, 1101-1103.)-With the exception of Shephards chromium phosphate (Cr,P,O,) chromium has hitherto only been found in traces in phosphates, and never, to the author’s knowledge, in calcium phosphates.In Algerian phosphates, however, which have recently become of considerable irn- portance in commerce, chromium appears to be a constant though small constituent. For the quantitative estimation of the chromium the author employs B m o d i b - tion of J. Clarke’s method of oxidation with sodium peroxide (Journ. Chenz, $oc., lxiii., 1079). Ten grammes of the phosphate are dissolved in the usual mixture of hydrochloric and nitric acida, and the filtrate and washings evaporated to a pasty con- sistency, in order to expel the excesg of acid. The moist residue is taken up in as small g quantity as possible of hydrochloric acid, oxidized by boiling with sodium peroxide, and the residue again treated in the same manner.The united filtrates and waabiags (oolafaining the chromium as sodium chromate) are boiled down, and in order to con- phbely remove the excess of sodium peroxide are again strongly diluted and evaporated. The liquid is then acidified, and the chromic acid titrated in the usual mauner.THE ANALYST. 53 In this way the author found 0.057 per cent. of chromic oxide in a large repre- sentative sample of Algerian phosphate. C. A. M. Volumetric Estimation of Molybdenum. F. A. Clooch and J. T. Worton. (Zeits. amrg. Clzem., 1898, xviii., 312.) -The iodometric method of estimabbg molybdenum outlingd by Friedheim and Euler (ANALYST, 1896, xxi., 25) suffers from tihe defect that the precautions taken to avoid the disturbing influence of atmospheric oxygen are by no means sufficient. To be fairly accurate, the prooess requires carrying out as follows : The amount of molybdate taken for analysis must not contain more than 0.3 gramme of MOO, ; the excess of potassium iodide over that decomposed by bha molybdate must not be greater than 0.5 gramme ; the liquid should consist of 20 G.C.of the stroageat hydrochloric acid and 20 C.C. of water; it must be boiled down till only 25 C.C. are left in the flask; and the distillation must be conducted in a current of carbon dioxide carefully freed from air. Even under these conditions an error, corresponding to some 0.3 milligramme of molybdenum trioxide, is intro- duced by the oxygen dissolved in the water and acid; to obtain the best results, therefore, these reagents should be boiled before use.As an alternative way of deterniining molybdenum, the moIybdate may be reduced to pentoxide by heating it with acid and an iodide in an Erlenmeyer flask lighkly dosed with a bulb-tube, boiling off the excess of iodine, making the liquid alkaline, and finally titrsting it with standard iodine solution. F. H. L. Note on Drown’s Method of Determining Silicon in Steel. G. Auchy. (Jour. Amer. Chem. Soc., 1898, xx., 547-549.)-There is some reason to believe that in determining the silicon in steel by Drown’s method some of it escapes dehydration owing to the fact that, as the sulphuric acid becomes more concentrated, part of the iron salts separate out and form a protecting envelope round the gelatinous silica. To obviate this the author suggests evaporating with aqua regia and sulphuric acid, instead of with nitric and sulphuric acids, the liquid being rapidly boiled down in a small porcelain dish on a very hot plate, with a, watch glass suspended over the basin by means of glass rods. In this way the iron salt is kept in solution until the very last moment, when it suddenly crystallizes out and fumes of sulphuric acid appear. If a second similar evaporation be made before filtering, it is hardly likely that any appreciable qumtity of die& will escape dehydration. A number of test andysee were made in this way with steeIs containing 0.25 per cent. of silicon, and not more than an additional 0.005 per cent. was obtained by the second evaporation. A steel which gave 0.122 per cent. with one evaporation gave 0.126 per cent. on repeating the malyais and evaporating twice before filtering. It is aleo stated that the evaporation proceeds quietly and without bumping or spurting, even at the moment of solidification and after, so that no attention is required. C. A. M.

ISSN:0003-2654    

DOI:10.1039/AN8992400051

出版商:RSC    

年代:1899

数据来源: RSC

摘要:

54 THE ANALYST, APPARATUS. (Anaer. Chem. Joumz., 1898, xx. 577-580.)-The essential pmts of this apparatus are: (1) h receiver A in the form of a cylinder (8 inches long and 6 inches in diameter) divided into three compartments b, c, and d by the partitions p and p‘. Between b and c is a circular opening 2 inches in diameter, and two smaller openings are placed between c and d. (2) An injector tube, E, 79 inches long and inch outside diameter, provided at the top with the A Hew Form of Water Blast. .” Fig 1. Rgm. f unnel-shaped projection g. (3) An outlet tube f with a diameter equal to that of I , extending up- ward from c and curving over and downward to g. The tube t (2- inch in diameter) opens intof and extends tog. Xis a stop- cock opening into d, and K a nozzle with an orifice attached to the upper part of f.The axes of K and I are made to exactly coincide. In action the cock X is opened, and the water turned on. The jet of water issuing from K passes through I and falls into the compartment b. When the level of the water in b rises above the - _ :6 inch in diameter lower end of the tube Z, a considerable volume of air is swept into A , escaping through f and S, and later through S only. The water flows from b into c through the opening in the partition. The cock X is now closed, and the increase of pressure in the receiver forces the wateis up through f and into g. The jet from Know strikes on the surface of the water in y and drives it down into A , together with a large volume of air. If the cock S be now opened a current of air of sufficient pressure to supply a large blast lamp will be obtained.Spurting is prevented by surrounding g with a cylindrical case h, having openings in the top to allow air to enter, and an overflow pipe 41 for the escape of water. Fig. 1 is a vertical section of the complete apparatus ; Fig. 2 is 8 projection from above; a d Fig. 3 a section through the middle of the receiver. The advantages claimed for this blast over that of Richards and that of Muenke are : That the orifice for the entrance of air and water is of such ample size that anyTHE ANALYST. 55 considerable friction is avoided; that owing to the injector tube being perfectly straight the jet of water is not deflected, and the maximum effect is obtained; and that the energy is transmitted to a much greater volume of water, which circulates continuously from f through I and acts as a piston which completely fills the cross section of the tube.This apparatus can be obtained from Eimer and Amend, New York. C. A. M. Apparatus for Increasing the Speed of Filtrations, H. von Winkler. (Chem. Zeit., 1898, xxii., 1066.)-This apparatus is specially suitable for the filtration of minute quantities of liquid where the use of the filter pump is impracticable. It consists essentially of a glass plate, one side ground true, having at its cenkre a tube projecting at right angles to which a rubber tube can be affixed. A funnel with a ground edge is carefully fitted with a strong paper and filled Kith the liquid ; the disc is placed on top and held in position with the fingers, while air is blown through the tube by means of the mouth, thus increasing the effective pressure.The disc may be of vulcanite, with a soft bearing surface if preferred; or the glass may be moistened (in order to make a better joint) with some of the same liquid as that under treatment. F. H. L. REVIEW. AN ATLAS OF BACTERIOLOGY. By CHARLES SLATER, M.A., M.B., M.R.C.S. prig.), F.C.S.; and EDMUND J. SPITTA, L.R.C.P. (Lond.), M.R.C.S. (Eng.), F.R.A.S. (London : The Scientific Press, Limited.) This work consists of 111 original photomicrographs, together with explanatory text, a photographic introduction, and a bacteriological introduction. The photo- graphic introduction will be found very useful to anyone who desires to keep a permanent record of his bacteriological results, containing as it does many practical hints on the selection of objectives and general optical apparatus.The reeults obtained by the authors show evidence of much patience and manipulative skill, while the process reproduction is excellent. I n the bacteriological introduction a description is given of the morphology and reproduction of the Xchizophytes. The photographic illustrations of cultures and microscopic appearances of the more important bacteria follow, together with a rhumb of the chief characteristics of each. Amongst other organisms, Bacillus nnthracis, B. tuberculosis, B. typhoszcs, B. coli communis, B. diphtheriw, SpirilLun8 cholera Asiatica are very fully illustrated. Attention is to be directed to plates 16 (B. anthracis, envelope), 17 (B.anthracis, spore formation), 18 (B. mzthrncis, stab culture), 53 (B. typhosus, gelatine streak culture), 60 (B. coli comnzzinis, gelatine streak culture), 69 and 70 (B. diplitlzeria, culture), and the plates illustrating the differentiation of Sp. cholera Asiatic@ (79 and SO), and Sp. Finklerii (84 and 85). I n a future edition it may be hoped that illustrations of colonies of many of the more important pathogenic and non- pathogenic organisms, as they appear when grown on phenolized agar jelly at 37" C., will. be added, for although they lqse many characteristics, yet it is in this orm that they are generally met with in the bacteriological examination-for instance, of water. The appearance of actual colonies and characteristic growths Price 7s. 6d.56 THE ANALYST. would seem to be of equal importance with the microscopical appearance of the organisms themselves. As it is, the book is one which every analyst should p s e s s for reference who systematically examines water bacteriologically. J. F. H. (3.

ISSN:0003-2654    

DOI:10.1039/AN8992400054

出版商:RSC    

年代:1899

数据来源: RSC

摘要:

56 THE ANALYST. INSTITUTE OF CHEMISTRY OF GREAT BRITAIN AND IRELAND. THE following is a list of the names of the candidates who passed the examination of the Institute of Chemistry held in January, 1899 : PRACTICAL EXAMINATION FOR THE ASSOCIATESHIP (under regulations in force prior to October 1, 1893)-Chapman, Arthur Jenner, Finsbury Technical College, London; and with Messrs. F. and A. C. Claudet, FF.1.C. Forster, Ferdinand Edward Paul, Finsbury Technical College ; registered student under Messrs. F. E. Lott, F.I.C., and C. G. Matthews, F.I.C. Lishman, George Percy, B.Sc. (Edin.), Surgeons’ Eall, Edinburgh ; registered student under Professor W. Ivison Macadam, F. I. C. INTERMEDIATE EXAMINATION (under new regulations) .-Aston, Staff ord, Univer- sity College, London. Blackman, Walter Lionel, Royal College of Science, London, and St.Bartholomew’s Hospital. Coysh, Basil Radcliffe, King’s College, London. Hewitt, Henry Dixon, Finsbury Technical College ; registered student under A. C. Chapman, Esq., F.I.C. Hill, Alfred, University College, Nottingham. Kinnersley, Henry Wulff, Merchant Venturers’ Technical College, Bristol, under Professor Julius Wertheimer, B.A., B.Sc., F.I.C. ; registered student under Dr. E. H. Cook, F.I.C.; and at King’s College, London. Rogers, John, Gltasgow and West of Scotland Technical College. Shedden, Frank, 3. Sc. (Lond.), Mason University College, Birmingham. Wright, Leonard Victor, B.A. (Cantab.), Sidney College, Cambridge. FKNAL EXAMINATION FOR THE ASSOCIATESHIP (under new regulatiom). - In Branch A (Mzneral Chemistry) .- Golding, John,* School of the Pharmaceutical Society ; Laboratory of the Royal Agricultural Society of England ; University College, Nottingham. Hancock, Walter Charles,* B.A.(Cantab.), Caius College, Cambridge ; with Mesirs. C. F. Cross, F.I.C., and E. J. Bevan, F.I.C. ; and at King’s College, London. Marshall, Arthur, A.C.G.I., City and Guilds of London Institute. In Branch B (Metallurgical Chmistry) : Imrie, John, Glasgow and West of Scotland Technical College. Wild, Boland Cecil, King’s College, London ; registered student under C. J. Head, Esq., F.I.C. In Brunch D (Oyganic Chemistry) : Gilles, William Setten, A.C.G.I., City and Guilds of London Institute. Hinks, Percy John, A.R.C.Sc. (Lond.), Royal College of Science, London. Joyce, Thomas Goode, B. Sc. (Lond.), Mason University College, Birmingham. In Branch E (the Analysis of Food a d Dmgs and of Water) : Gilbard, John Francis Hutchins,* Finsbury Technical College ; and with Dr. Bernard Dyer, F.I.C. Hackman, Charles Adolphus, King’s College, London; and with A. C. Chapman, Esq., F.I.C. Young, Francis Samuel, M.A. (Oxon.), Queen’s College, Oxford, and Caius College, Cambridge. The examiners were Professor Percy F. Frankland, F.R.S., F.I.C., and Otto Hehner, Esq., F.I.C. * For the Fellowship.

ISSN:0003-2654    

DOI:10.1039/AN8992400056

出版商:RSC    

年代:1899

数据来源: RSC

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THE ANALYST. MARCH, 1899. PROCEEDINGS OF THE SOCIETY OF PUBLIC ANALYSTS. THE annual general meeting of the Society was held on Wednesday, February 1, in the Rooms of the Chemical Society, Burlingtdn House, the President (Dr. Bernard Dyer) occupying the chair. The minutes of the extraordinary general meeting and of the ordinary general meeting, held on January 4, were read and confirmed. Certificates of proposal for election to membership in favour of the following candidates were read for the first time : Percy T. Adams, assistant to Dr. Matthew A. ddams, Maidstone; Arthur French Angell, assistant to Mr. Arthur Angell, Southampton ; John B. Ashworth, assistant to Mr. Alfred Smetham, Liverpool ; Alfred Joseph Bull, assistant to Mr. Wm. Chattaway, and senior assistant in the Physical Laboratory, Birkbeck Institution, London ; Charles Crocker, assistant to Messrs.Morgan, Son and Seyler, Swansea; John S. Ford, analytical chemist, Edinburgh; C. A. Hackman, A.I.C., assistant to Mr. Alfred C . Chapman, London; Norman Leonard, B.Sc., F.I.C., assistant to Dr. Stevenson, Guy’s Hospital, London ; J. F. Liverseege, F.I.C., assistant analyst to the Corporation of Birmingham ; Richard Murray, chemist to Messrs. Brotherton and Co., Leeds; G. E. Scott- Smith, F.I.C., assistant to Mr. Alfred H. Allen, Sheffield ; W. P. Skertchly, assistant to Mr. Otto Hehner, London; Harry Metcltlfe Smith, F.I.C., assistant to Dr. Stevenson, Guy’s Hospital, London ; Lionel W. Stansell, assistant to Dr. Matthew A. Adams, Maidstone; and W. Northfield Yarrow, assistant to Mr.A. W. Stokes, London. All of these candidates were former associates of the Society, applying for election to membership under the revised rules recently adopted. Mr. F. C. J. Bird and Mr. .J. H. Heywood were elected members of the Society. The RON. TREASURER (Mr. E. W. Voelcker) presented his report for the past year. He stated that the Society had a balance of M O 5s. 5d. standing to its credit, as against $32 12s. 8d. shown in the balance-sheet for 1897. The items most calling for attention were those classed as ‘‘ General Expenses,” and relating to postages, petty disbursements, etc., and the printing and stationery account. I t would be seen, from the copies of the accounts which had been placed in the hands of the meeting, that these items showed a considerable increase as compared with the previous year.During 1898, however, the Council had considered it desirable to circulate among Members of Parliament, and among County Councils and other local authorities, a58 THE ANALYST. report of the Council of the Society of Public Analysts dealing with the Sale of Food and Drugs Bill introduced by the President of the Local Government Board at the close of the session of 1897. This had involved a considerable outlay in printing, and a very heavy expenditure on postage. The securities of the Society on December 31 were the same as in the previous year; but since that date he had been able to make a further investment on behalf of the Society, so that its invested funds were now increased by 2,105. He was pleased to be able to announce that only one subscription remained outstanding.A vote of thanks to the Hon. Treasurer and Auditors was proposed by Mr. CHAPMAN, seconded by Dr. SCHIDROWITZ, and carried unanimously. The President then delivered his retiring address. Mr. ALFRED H. ALLEN proposed a vote of thanks to the President for his address. Mr. HEHNER seconded the proposition, which was put to the meeting by Mr. Allen and carried unanimously. The PRESIDENT, having responded, moved from the chair that a vote of thanks should be passed to the President and Council of the Chemical Society for allowing the Society of Public Analysts the use of their rooms during the past year. The motion was seconded by Mr, CHATTAWAY and carried unanimously. The PRESIDENT announced that the officers and Council for 1899 had been elected in accordance with the nominations made by the Council at the December meeting of the Society.He then vacated the chair in favour of the newly-elected President, Mr. W. W. Fisher, M.A. Mr. FISHER, having assumed the chair, expressed his appreciation of the honour which the Society had done him in electing him to occupy that position, and the proceedings then terminated. The following is a list of the officers and Council of the Society for 1899 : President. -W. W. Fisher, M.A. Past-Presidents. -M. A. Adams, F.R.C.S.; A. H. Allen; Sir Charles A. Cameron, M.D., F.R.C.S. ; A. DuprB, Ph.D., F.R.S. ; Bernard Dyer, D.Sc. ; Otto Hehner ; Alfred Hill, M.D., F.R.S.E. ; J. Muter, M.A., Ph.D., F.R.S.E. ; Thomas Stevenson, M.D., F.R.C.P. Vice-Presidents.-Charles E. Cassal; E. W. T. Jones ; S. Rideal, D,Sc. Hon. Treasurer.-E. W. Voelcker, A.R.S.M. Hon. Secretaries.-E. J. Bevan, Alfred C. Chapman. Other Menzbers of C'ouizciL-Bertram Blount ; Sidney Harvey ; Arthur R. Ling ; C. A. Mitchell, B.A. ; C. G. Moor, M.A. ; James Nimmo ; Thomas A. Pooley, B.Sc. ; F. Wallis Stoddart; R. T. Thomson; John White; Rowland Willianls; W. C, Young.

ISSN:0003-2654    

DOI:10.1039/AN8992400057

出版商:RSC    

年代:1899

数据来源: RSC

摘要:

THE ANALYST. 59 ADDRESS OF THE RETIRING PRESIDENT. (Delivered at the Meeting, Pebruary Ist, 1899. IN addressing you at the close of 1897, I had the melancholy duty of recording the deaths of an illustrious honorary member of the Society and of three ordinary members. This year, I regret to say, we have again to record the death of an illustrious honorary member, Lord Playfair, whose chemical career is sufficiently well known to chemists to render it unnecessary for me now to do more than call attention to the fact that it was in recognition of his interest in the question of food adulteration, and of his successful exertions in the House of Commons for the improvement of the Bill passed in 1875, that he was elected an honorary member of this Society. During the past year also we have again lost hy death three ordinary members.One was our late lamented Vice-president, John A. R. Newlands, a, chemist of remarkable ability, whose name will long live in connection with the history of the development of chemical thought during our time, on account of his early enunciation of what has since become known as the Periodic Law of Newlands and Mendelejeff. He was a very old and universally beloved member of this Society, and the rooms of the Chemical Society and other haunts of London chemists have been sadder and duller during the present session by reason of the disappearance froni among us of his bright face and genial voice. Mr. J. Napier and Mr. F. P. Perkins, whom we have also lost during the year, were both old members of the Society, though they had not been in the habit for many years of attending its meetings. Mr.Napier was well known as Public Analyst for the borough of Ipswich and for the county of Suffolk, while Mr, Perkins had for many years occupied the position of Public Analyst for the city of Exeter. Seven members of the Society resigned their membership during the year, and four associates were elected to the full membership of the Society. I n addition to these, we elected five other new members and five associates. The net consequence of these changes is that we numerically lost one honorary member and one ordinary member, gaining one associate. The following figures show the numerical condition of the Society for the last four years : January, 1896. January, 1897. January, 1898.January, 1899. Honorary members . . . 10 11 11 10 Members ... ... ... 210 218 223 222 Associates ... ... 26 29 31 32 246 258 265 264 _- - - This is perhaps a fitting place for congratulating the Society upon having recently adopted, on the advice of the Council, a considerably modified scheme of constitution and rules. The changes which have been made had been for a long time under the consideration of the Council and officers of the Society, and I hope and believe that they will result in a gain on the part of the Society, in efficiency as well as in numerical strength. It is scarcely necessary t o remind you, except for historical purposes, of the60 THE ANALYST. principal change which has been made. I told you that at the close of 1898 we had thirty-one associates ; now we have no associates.It was formerly our rule that only the practising analyst, or the analyst having such control of a laboratory as to render him virtually a practising analyst, as distinct from an assistant, was eligible for election to our membership. The consequence was that many of our associates were well qualified chemists approaching middle age, and the position of some of them was becoming every year more and more anomalous; and we had also reason to believe that a number of chemists who could not technically qualify for membership without unduly straining our old rules, had remained outside of the Society rather than join the junior ranks of the associates. In this way, we considered that, if the Society had not actually suffered, it had at all events unnecessarily limited its strength.The range of our work has gradually grown wider, and the very large variety of analytical questions now dealt with in the pages of the ANALYST, and the always increasing circulation of that now indispensable journal, have attracted many friends and sympathizers at home and abroad, to whom we have felt that it would be graceful to open the doors of the Society, should they care to enter into closer and more friendly intercourse with us than existed in merely studying the literature which we placed beEore them month by month'in our journal. We have therefore repealed our old enactment as to the qualifications for membership, substituting a simpler require- ment, so that anyone not less than twenty-one years of age, engaged in the profession of analytical chemistry, shall be eligible for proposal for the full membership of the Society, under the conditions laid down in the rules, which will shortly be distributed among you.Additional copies of these you may obtain from the honorary secretaries, in case any of your chemical friends express to you a desire to become acquainted with them. That the change is not generally distasteful to our old associates may be gathered from the fairly long list of those whose names have been proposed this evening for transference to the rank of members, This has been already ably placed before you by our honorary treasurer. The thoroughness with which he discharges his duties is evidenced on the one side of the account by his success in gathering in our subscriptions, while on the other side, despite the iiiany calls on his purse, he is able to show a sufficient saving to increase, even though not to a very large extent, the Society's funded property.The ANALYST is necessarily an expensive undertaking, and, in addition to our other normal or necessary expendi- ture, we have during the past year expended a great deal of money in printing and postage, in connection with the distribution among members of Parliament, county councils, borough corporations, and other local authorities, of the views of the Society, as represented by its Council, on matters connected with proposed new legislation on the question of adulteration. The ANALYST, with its present large circulation, is, even from a purely business point of view, no light undertaking ; and, with the exception of those who have served on the Council-or rather on the Editorial Committee-few of you probably fully realize the labour necessarily spent, both by our editor, Dr.Sykes, and by our honorary treasurer, Mr. Voelcker, on the mere accounts of the journal," and matters incidentally relating thereto. The I need not detain you by much reference to our financial condition.THE ANALYST. 61 treasurership of the Society in early days was a very light task, but it has now grown to very serious proportions, and is really a very formidable consumer of the time that is so faithfully and ungrudgingly given to it by the present occupant of what I now regard as the most important office on the Council.Although I have thus ventured to crave your recognition of the care given to your business affairs by our treasurer and by our editor, it would seem hardly necessary that I should mention, as a self-evident subject for our gratitude, the literary labour spent by the latter on our monthly journal. We have an editorial committee, and that committee works loyally, and works hard, in the duties alIotted to i t ; and we have an industrious and able staB of abstractors. But the success of such a journal must always necessarily depend mainly upon the constant daily work of its editor-. work which, in the case of Dr. Sykes, may be almost said to be gratuitous; for, although we give him an honorarium for his services, it is an honorarium which has no relation whatever to the work that he does.Happily, he is a, man of leisure, and still more happily, he is willing to devote that leisure to the good cause of editing and managing this journal. Our editor has had still more to do during the past year than heretofore in the editing of abstracts. I cannot help wishing, however, that we had given him more original papers to edit, During the past year only twenty-one original ,papers have been read before the Society. Most of these have been published in the ANALYST, together with three other original papers. Of abstracts of papers of interest to the analytical profession, published abroad, or elsewhere than in the ANALYST, we have during the year published 296, as against 283 in 1897, and 246 in 1896. The following table shows the respective numbers of abstracts in each of these years, published under the various headings of Food and Drugs Analysis, Toxicological Analysis, Organic and Inorganic Analysis, and Apparatus.ABSTRACTS PUBLISHED IN THE ANALYST. 1896. 1897. 1898. Food and Drugs Analysis ... . . ... 55 86 72 Toxicological Analysis . . . ... ... 9 5 3 Organic ?, ... ... ... 86 87 109 Inorganic 7 7 ... ,.. ... 86 91 89 Apparatus ... ... ... ... 9 14 23 245 283 296 - The following were the papers read before the Society during the year : “ Copper ‘ Pure for Analysis.’ ” “ Note on the Tests for Distinguishing Boiled from Unboiled Milk.” ‘( The Composition of Milk and Milk Products.’’ ‘‘ The Calculation of Added Water in Adulterated Milk.” By H. Droop Richmond. (‘Japanese Wood Oil.” ‘‘ A Typical North-East Lancashire River.’’ By F.R. O’Shaughnessy. The Analysis of Marmalade.” (‘ A New Form of Condenser.” By J. W. Westmoreland. By Hanry Leffmann, M.D. By H. Droop Richmond. By John H. B. Jenkins. By L, Kidgell Boseley. By Cecil H. Cribb.62 THE ANALYST. “Water Supply in Relation to the Maidstone Epidemic.” ‘( Note on Some Apparatus.” “ Sewage Analysis, and Standards of Purity for Effluents.” By C. G. Moor, M.A. “ Note on Certain Resins.” By Rowland Williams. “The Proportion of Oxygen Present in Linseed Oil, both before and after Oxidation.” By Rowland Williams. “ Chicory, and Variations in its Composition.” ‘‘ The Sulphuric Acid in Portland Cement.” “ A Curious Meat Preservative.” ‘‘ A Method €or the Quantitative Separation of Acetic and Valeric Acids.” By “ Contributions to the Chemistry of Drying Oils, with a Method for the Exami- ‘‘ Automatic Pipettes and Burettes.” ‘‘ The Effects of Recent Drought on the Quality of Milk.” “ On the Use of the Micro-Spectroscope, and the Methods of Detecting Blood The following original papers were also published in the ANALYST.“ Note on the Volume Concentration of Condensed Milk.” ‘‘ Note on the Examination of Liniment of Camphor.” By Norman Leonard, B.Sc., “ The Relation between the Specific Gravity and the Insoluble Fatty Acids of By Matthew A. Adams, F.R.C. S. By H. Droop Richmond. By Bernard Dyer, D.Sc. By Eug. Ackermann. By Alfred C. Chapman. Alfred C. Chapman. nation of Linseed Oil.” By Otto Hehner and C. A. Mitchell, M.A. By A. W. Stokes. By A. W. Stokes. in Chemico-Legal Investigations.” (Lecture.) By Alfred H.Allen. By A. McGill. and H. Metcalfe Smith. Butter and other Fats.” By Norman Leonard, B.Sc. I ventured last year to point out that many chemists read before other societies, or published elsewhere, papers which I thought ought properly to be read and discussed at the meetings of this Society, which alone of the many chemical societies is the one which is mainly and essentially devoted to the study of chemical analysis. I still think that this is in some sense due to the fact that many suppose that we do not care to discuss here papers dealing with subjects other than those cognate to matters coming before public analysts in connection with their statutory duties under the Sale of Food and Drugs Acts. I t has been at various times urged by many members, that we should attract more papers to our Society were we to drop the word “Public” from our title.While much is to be said for, as well as against, such a change in our title, and as the suggestion has been again made quite recently, I would repeat what I think I said at our recent Extraordinary General Meeting, viz., that the proposition to change our name has been long and seriously discussed by your Council, with the result that we have thought it better for the Society to advise you to retain the old colours under which you have now sailed well for five-and-twenty years. I hope, however, that the change recently made in the wording of our rules may induce some who are-not to use the word offensively- guilty of reading elsewhere analytical papers which ought to be read here, to at once seek to become enrolled as members of this Society, and to henceforth read their contributions to the literature of analytical chemistry at our meetings, where theyTHE ANALYST. 63 may surely expect to meet with a fairer appreciation than is often possible in other societies, which deal only occasionally and incidentally with analytical matters.I ventured last year to express satisfaction that the Institute of Chemistry, under the able presidency of our own late President, Dr. Stevenson, was about to see its way to granting a special diploma in pharmacology and therapeutics, such as would enable candidates for public analystships to produce the evidence of qualifica- tion required by the Local Government Board in these subjects as well as in chemistry.The arrangements then in contemplation have been completed, and the Council of the Institute now holds a special examination in these subjects, for such members of the Institute as may care to present themselves. The Institute of Chemistry is now, therefore, able to furnish the full evidence of qualification required by the Local Government Board, without a candidate being obliged to have recourse to any other Society or corporation, whether medical or pharmaceutical, or to merely individual or personal testimony as to therapeutical knowledge, which was always vague and unsatisfactory, and the acceptance of which by the Local Government Board was always a matter of uncertainty and difficulty.Whether the Local Government Board is technically right in demanding therapeutical and pharmacological qualifica- tion from the candidate for a public analystship before confirming his appointment is a somewhat vexed question which I do not propose to discuss. The fact exists that the demand is made, and it appears to be satisfactory that we can now meet it from our own recognised chemical diploma-granting body, via,, the Institute of Chemistry. Certainly no public analyst can be the worse for a fair knowledge of crude drugs, even though their examination may not come within the scope of his normal duties ; and it certainly appears to be educationally healthy and desirable that a, student who is taking, as his final examination for the associateship of the Institute, the section which relates more especially to the analysis of food and drugs, should learn sufficient practical materia medica to enable him to pass this examination.Not the least interesting to analysts among the chemical events of the year has been the completion, by the issue of its last volume, of the great work of our esteemed Past President, Mr. Allen, “ Commercial Organic Analysis,” a work which, whatever modification or extension it may have to undergo in the future, as our science develops, must necessarily live as one of the classical achievements of chemical literature, preserving the name of Allen side by side with the names of Gmelin, Watts, and Fresenius. The undertaking has been almost a stupendous one, having regard to the rapid daily growth of the subjects of which it treats.I n 1875 the most comprehensive treatise of the kind, then fairly up to date, was Prescott’s little manual on “Proximate Organic Analysis,” a book of only about 180 small octavo pages. A glance through that little book, to the eye now familiarized to the use of Allen’s splendid manual, perhaps brings home to one more cogently and more concentratedly than anything else the vast progress made by analytical chemistry during the last five-and-twenty years. Allen has not been merely the chronicler of this progress. He has largely been a contributor to it, not merely by the contribu- tions emanating from his own laboratory, which have been many and valuable, but by the educational and stimulating influence of the publication of his book.I like64 THE ANALYST. to think that, if not actually responsible for the birth of Allen’s book, the Society of Public Analysts has nevertheless had no small share in indirectly encouraging and influencing its progress and development. Although, as it appeared volume by volume, it has appealed to a world-wide circle of readers, yet I venture to think that the appreciation and personal encouragement which he has found in the little brother- hood of chemical friends banded together in this Society, have done not a little towards enabling its author to persevere unflinchingly in the heavy task to which he has devoted the best years of his life ; and I like to think, when reviewing the great progress made in proximate organic analysis during the last quarter of a century, that, in many directions, the lines of investigation, abroad as well as at home, were first marked out by the early work of inembers of this Society.The question which has engaged the attention of the Society now for some years still remains unsettled-I mean, the question of reformed legislation with regard to food adulteration. A year ago the only progress to be chronicled was that a Bill had been introduced into Parliament by the President of the Local Govern- ment Board, at the very end of the session of 1897, and simultaneously withdrawn. The Bill was a fragmentary and incomplete one, which failed to deal with the most important of the recommendations contained in the report of the Select Committee of the House of Commons on Food Products Adulteration, and was admittedly only put forward as a tentative measure. Your Council deemed it wise to criticise this Bill somewhat severely ; and the Bill met with so much severe criticism from so many other directions that it was not reintroduced.The President of the Local Govern- ment Board appears to have then come to the conclusion that the subject was too knotty a one to be dealt with as a whole, and he accordingly, after another session’s reflection, proposed-and, as before, simultaneously withdrew -another tentative measure, based on quite different lines, in which he proposed to deal only with agricultural products, to the exclusion of food articles of general manufacture. Such a Bill necessarily left undealt with a great proportion of the recommendations of the Food Products Adulteration Committee, though it partially embodied the spirit of the recommendation with regard to a standing authority to lay down standards or limits of composition.The Bill contained the following clause : The Board of Agriculture may, after such inq, they deem necessary, make regulations for determining the extent to 3h any deficiency in any of the normal constituents of milk or butter, or the presence of any foreign matter in any sample of milk or butter, shall raise a presumption, until the contrary is proved, that the milk or butter is adulterated or impoverished. I take it that the intention was that the Board of Agriculture should from time to time, as it deemed advisable or necessary, itself appoint a committee to talke evidence and make recommendations ; and it is quite possible, if the only articles to be dealt with were milk and butter, that the Board of Agriculture, acting with the assistance of a departmental committee appointed by itself, might satisfactorily take the place of the comprehensive standing committee of reference recommended in the report of the Select Committee.But, in the Bill of 1898, no machinery was provided for discharging the many other functions, connected with food generally,THE ANALYST. 65 which it was proposed should be assigned to the committee of reference contem- plated in the Select Committee’s report, It has been recently announced, on Government quthority, that the President of the Local Government Board has handed over the charge of the Bill to the President of the Board of Agriculture.Mr. Walter Long, in a recent speech, announced his intention of introducing during the coming session a Bill which he hoped would reduce adulteration, though from his speech it is to be feared that it will again be a Bill dealing only with food products produced by farmers. Mr. Long, however, stated, in effect, that he had been much struck by the general unanimity of the demand for fresh legislation, and that he had been approached by traders of all kinds, and by various commercial associations, far more than by agricultural interests. He was assured that there was wholesale adulteration going on in the country, and believed there was truth in the statement. He further said that it was a remarkable fact that all the statements which were made were on one side, and that no one had suggested that there was another side to the question, every assertion being to the effect that there was a great deal of frmd being perpetrated.He was satisfied that it was not a state of things that ought to be allowed to continue, and it was the intention of the Government to introduce, through himself, in the coming session, a Bill which he hoped would enable them to deal satisfactorily with the question, Perhaps it is not too late to hope that Mr. Long will yet find himself able to enlarge Mr. Chaplin’s Bill in such a way as to deal comprehensively with the question. Such a, Bill we all believe must ultimately come, and to deal with the whole question piecemeal is only to prolong the unsettled condition of affairs which has been so long causing concern to so many sections of the public.The mere question of the regulation of the use of dangerous preservatives and colouring matters is at the present time so vexed a one and so pressing a one that it would be anomalous if any Bill were introduced which did not hold out some satisfactory means of dealing with it.* The Council of this Society has more than once had its attention directed to the action of certain County Councils in undertaking to make, for the general public, in their own laboratories and at the hands of their own exclusively-engaged public analysts or medical officers, at the expense of the county rates, analyses of water and other articles at merely nominal charges, thus entering into competition with the ordinary practitioner of analytical chemistry.The Council has obtained from the Local Government Board a distinct expression of opinion to the effect that County Councils, in applying the county rates for such purposes, are exceeding their statutory powers. It is sincerely to be hoped that the effect of this declaration will be to put an end to so unfair and so unwarrantable a form of competition. I cannot close this somewhat random dissertation without referring to the very pleasant summer meeting, in which so many of us joined, at Woburn, where Dr. J. A. Voelcker was good enough to show us over the experimental farm which has been under the charge successively of his late father and of himself for over twenty years. I n historical interest the Woburn farm has now become second only to the older station at Rothamsted, and many of our members were pleased to J[. Since this address was delivered Mr.Long has introduced his Bill (February 23) into the House of The scope of the Bill is wider than that of the Agricultural Bill introduced last year. Commons.66 THE ANALYST. have the opportunity of visiting it. The recently established pot-culture station, established for the purpose of carrying out investigations on the influences of various chemical substances on plant growth, under the bequest of the late Mr. Hills, was very interesting to most of us ; and the kindness of the Duke of Bedford in throwing open to our inspection the art treasures of Woburn Abbey added pleasantly to the attractions of a most enjoyable meeting. I close this evening an official connection with the Society extending over sixteen years, fourteen years as one of your secretaries, and two years as your President. And I feel that it would be unbecoming did I not now, in taking my official farewell of you, say how much of the happiness of my life has been due to friendships formed in this Society, and did I not also make some formal acknowledgment of the much kindness-and often, I fear, much for- bearance-which you have extended to me in the face of many shortcomings, some of them conscious, and some of them (and usually these are the worst) not conscious. Not to make blunders, however, is a gift proverbially reserved for those who make nothing. Mine you have been good enough year after year to overlook, and my best consolation is thcx,t the Society has flourished in spite of them. My seat in this chair I now resign to an able and accomplished successor. My old secretarial chair, which during the last two years has been occupied by Mr. Cassal, will from this evening be occupied by a, gentleman who is not a very old member of the Society, but who is a, very loyal one. Mr. Chapman is a chemist of distinguished ability and a man of energy and industry, and he will have a good trainer in his new duties in my old colleague, Mr. Bevan, who still happily retains his post. Now a brief personal word.

ISSN:0003-2654    

DOI:10.1039/AN8992400059

出版商:RSC    

年代:1899

数据来源: RSC

摘要:

66 THE ANALYST. ANNUAL DINNER OF THE SOCIETY OF PUBLIC ANALYSTS, THE annual dinner was held at the Criterion Restaurant, after the annual meeting, under the chairmanship of the newly-elected President, Mr. W. W. Fisher, M.4. About sixty members and guests were present. Amongst the latter were Professor Odling, F.R.S. ; Professor Tilden, F.R.S. ; Dr. Thos. Stevenson, President of the Institute of Chemistry ; Mr. Walter Hills, President of the Pharmaceutical Society ; Mr. George Beilby, President of the Society of Chemical Industry; Dr. Childs ; Dr. Longstaffe; Dr. Pakes; Mr. E. Holmes; Mr. F. W. Beck; and Mr. Aubrey W. Rake. The following toasts were proposed : (‘ The Queen,” by the President ; ‘‘ The Institute of Chemistry,” by Professor Odling, F.R.S., responded to by Dr.Thos. Stevenson, President of the Institute ; ‘( Kindred Societies,” by Dr. Bernard Dyer, responded to by Mr. Walter Hills, President of the Pharmaceutical Society ; (‘ The Society of Public Analysts,” by Professor Tilden, F.R.S., responded to by the President; and ((The Guests,” by Mr. Otto Hehner, responded to by Mr. George Beilby, President of the Society of Chemical Industry.66 THE ANALYST. ANNUAL DINNER OF THE SOCIETY OF PUBLIC ANALYSTS, THE annual dinner was held at the Criterion Restaurant, after the annual meeting, under the chairmanship of the newly-elected President, Mr. W. W. Fisher, M.4. About sixty members and guests were present. Amongst the latter were Professor Odling, F.R.S. ; Professor Tilden, F.R.S. ; Dr. Thos. Stevenson, President of the Institute of Chemistry ; Mr. Walter Hills, President of the Pharmaceutical Society ; Mr. George Beilby, President of the Society of Chemical Industry; Dr. Childs ; Dr. Longstaffe; Dr. Pakes; Mr. E. Holmes; Mr. F. W. Beck; and Mr. Aubrey W. Rake. The following toasts were proposed : (‘ The Queen,” by the President ; ‘‘ The Institute of Chemistry,” by Professor Odling, F.R.S., responded to by Dr. Thos. Stevenson, President of the Institute ; ‘( Kindred Societies,” by Dr. Bernard Dyer, responded to by Mr. Walter Hills, President of the Pharmaceutical Society ; (‘ The Society of Public Analysts,” by Professor Tilden, F.R.S., responded to by the President; and ((The Guests,” by Mr. Otto Hehner, responded to by Mr. George Beilby, President of the Society of Chemical Industry.DIAGRAM No. 2.

ISSN:0003-2654    

DOI:10.1039/AN8992400066

出版商:RSC    

年代:1899

数据来源: RSC

摘要:

THE ANALYST. Nature of Strata. Varieties mentioned in Section Diagram. Shale . . . . . . Black, blue, light blue, dark blue, soft blue, gray, dark, sandy, variegated. Sandstone . . Brownish mottled, broken, coarse, close - grained, fine, greenish gray, dark gray, hard gray, open gray, reddish, , I shaley, streaked, variegated, white. - I - Millstone grit Coal . . . . . . Fire clay . . . . . . . - - -_ - Miscellaneous - __ - - - ..* I ... Beryl, blue bind, sandy bind, clay, clunch, ironstone, lime- 67 Total Thickness in feet. - -. 1,100 350 300 17 16 20 THE OCCURRENCE OF BARIUM COMPOUNDS IN ARTESIAN WELL WATER. BY JOHN WHITE, F.I.C. (Read at the Meeting, January 4, 1899.) THE presence of a salt of the metal barium in solution in a natural water in this country is in my experience of very rare and unusual occurrence.I can only find a few instances recorded of the existence of a soluble salt of this metal as a constituent of unartificial waters, and therefore think it desirable to lay before this Society the results of my analyses of some samples of water derived from an artesian well of very great depth at Ilkeston in Derbyshire. I give all the information I have been able to obtain respecting the bore-hole, and exhibit .drawings in section of the strata passed through, which are here reproduced (see diagrams 1 and 2). For much of this information I am indebted to Mr. Henry J. Kilford, the Borough Surveyor of Ilkeston, also for the loan of the drawings. The bore-hole, the surface of which is 160 feet above sea-level, O.D., has been carried to a total depth of 1,801 feet, water being found at 837 feet, and rising to a height of 15 feet above the surface.As only about 180 gallons per hour were obtained at the surface from that depth, the bore was deepened as stated, with the result that the yield remained practically unaltered. A pumping shaft was then sunk round the bore-hole to a depth of about 150 feet, and this is now in course of being deepened to about 300 feet. The steel tubes were removed as the sinking proceeded, and a considerable increase in the volume of water yielded has been the result, great difficulty being experienced at times in plugging up the tube. It was during the removal of a length of tube that the accident happened which caused the admittance to the bore-hole of the abnormal water presently to be described.Mr. Kilford is of opinion that the tubes split somewhere lower down, and by sinking the shaft below the Kilburn coal measures, he expects to be able to " tub out " the abnormal water. The bore-hole was lined with steel tubes to a depth of 1,040 feet. The diagrams give exact particulars of the nature and thickness of each layer of the strata passed through. By adding together the figures given for the various layers of like material, and grouping them according to their general description and classification, arough synopsis of the formation is obtained, as shown in the following table : TABLE I.68 THE ANALYST. Before proceeding further to consider the nature of the strata, I give in the next A is the water originally yielded by the bore-hole.B is the abnormal water which gained access to the bore-hole, as is supposed by the splitting of the steel lining tubes. C is a similar sample, collected about six months later than B. D is from the pumping shaft, collected since this abnormal water appeared. E and F are from the pumping shaft, taken about 80 feet below the surface, table the results of my analyses of six samples of water : before the abnormal water was found. TABLE 11. Results expressed in Parts per 100,000, Total solid matter, dried a t 100" C. Saline residue . . . . . . . . . Free and saline ammonia . . . . . . Albuminoid ammonia . . . . . . Nitrogen in nitrates and nitrites Oxygen absorbed in four hours a t 80" F. . . . . . . . . . . . . Hardness by soap test : Loss on ignition .. . . . . . . . Temporary . . . . . . . . . Permanent . . . . . . . . . Total . . . . . . . . . Silica . . . . . . . . . . . . Iron oxide, Fe,O, . . . . . . . . . Barium oxide, BaO . . . . . . Calcium oxide, CaO . . . . . . Magnesium oxide, MgO . . . . . . Potassium oxide, K,O . . . . . . Heavy metals . . . . . . . . . . Sulphuric anhydride, SO, ... CaCO, . . . . . . . . . . . . Sodium oxide, Na,O . . . . . . Chlorine . . . . . . . . . . . . Phosphoric anhydride, P,O, . , Total alkalinity, calculated aH Alkalinity after boiling, calcu- lated as CaCO, . . . . . . Alkalinity after boiling, equiva- lent t o Na.&O, . . . . . Specific gravity at 60" F. water 1.000 . . . . . . . . . . . . Appearance in 2-feet tube .. Odour . . . . . . ! . . . .. Taste . . . . . . : . . . . . From Bore-hole. A c . A. 59.5 3-0 5 6 5 0*060 0'002 0.0 0.036 -- - - 7.71 0.0 Traces. 1.38 2.60 Traces. 0.0 - Absent. 17.1 0.0 0.0 26.5 21 *25 22.52 -- - Fairly clear ; brownish- green. None. None. B. 2628'0 194.0 2434'0 -~ 0-875 0.004 0.0 0.680 - - - 0'0 4.5 28-36 141.64 42-16 0.0 1080 -76 Absent. 1491.0 0.0 0.0 20'0 2.0 - - 1.018 Turbid ; brownish- green. Slight. Strongly saline. C.. -- 2752.0 198.0 2554.0 - - 0.0 - - -- - 1.2 1-6 29.94 169.0 39.06 0'0 1109~1s Absent. 1554-9 0.0 0.0 19.0 1% - ~- 1.019 Turbid ; brownish- green. Slight. Strongly d i n e . From Pumping Shaft. h r \ D. 1 E. -- 282.0 162:- 19'0 I - 263.0 0.120 0.006 0.0 - 21-03 23-22 44.25 1.0 1.2 2.23 15-40 4.82 0.0 114.02 Absent. 142.0 0.0 0-0 25.0 2 -5 - - L'urbid an( >palescent brownish- green.None. Saline. -- 0~100 0'008 0.055 0'124 13-58 7 *02 20.80 Traces. 0.0 - - - - - Absent. 10 5' - - 34.5 21.5 22.79 --- - Rather turbid anc ,palescent brownish- green. None. None. F. 51 *O __ - .- 0-080 0.004 0.055 0.035 13-26 7'14 20.40 Traces. - 0.0 - - - - Absent. 4.8 ._ - 34.0 21 *o 22-26 ~ - Rather ;urbid and )palescent ; brownish- green. None. None..THE ANALYST. These waters are of peculiar and abnormal composition. Samples E and F are of no great interest, and are only included as indicating the kind of water occurring in the neighbourhood of the bore-hole; they are typical examples of water such as is frequently found in or near the coal measures, containing, as these samples do, a comparatively high amount of free ammonia and ch€orine, with traces of iron and a considerable quantity of sodium carbonate.The first four samples contain barium in varying amount, and there is conse- quently an entire absence of sulphates and phosphates. As compared with the total solid matter present, the proportion of chlorine is relatively exceedingly high, while the lime and magnesia are in each instance very low. There is no evidence of pollution, the free ammonia being doubtless of mineral origin, and organically the waters may be pronounced to be pure. Sample A was decidedly alkaline from presence of sodium carbonate, a fact which renders the occurrence in the water of barium particularly remarkable, inasmuch as sodium carbonate will precipitate the chloride or other soluble salt of barium at the ordinary temperature and in very dilute solutions. The barium, therefore, must exist as the carbonate, which salt is slightly soluble in water ; it is present to the extent of 1.77 parts per 100,000.This water flowed from the bore-hole at a temperature above normal ; at the date of collection the thermometer in the open registered 47" F., but the temperature of the water was 61" F. B and C closely resemble each other in their phenomenal composition; they contain an amount of barium corresponding respectively to 38.55 and 40.70 parts per 100,000 of barium chloride. With the exception of a water stated by Professor Bedson (J.X.C.I., vol. vi., p. 712) to contain 96.04 grains per gallon of barium chloride, this is the highest amount I have been able to find recorded as occurring in a natural water.The other features of these waters worthy'of notice are the extraordinary quantity of common salt in solution, and the comparatively small amounts of lime and magnesia present. When freshly obtained, samples B and C, upon being briskly shaken at the ordinary temperature, evolved a considerable amount of gas, which I believe mainly consisted of nitrogen. Sample D appears to consist of some similar water to B or C, diluted to nearly ten times its volume with some other normal water; the solid matter, chlorine, barium chloride, lime and magnesia, are present approximately in about one-tenth the amount in which these constituents occur in samples B and C. I n Table 111. I have combined the acids and bases to show what may probably represent the actual salts present iu solution in the four waters containing barium.It frequently happens that there is a difference of opinion as to the method to be adopted in combining these acids and bases I have no wish, therefore, to insist upon the correctness of the view I have taken, but simply to follow the usual custom and state the calculated analyses : Samples B, C, and D all contained barium chloride.70 Calculated Analysis. A. ---- Barium carbonate.. . ... 1.77 Calcium carbonate ... 4.64 Sodium carbonate . . . ... 22.52 Sodium chloride ... ... 28.17 57.10 -- Silica ... ... ... - .Oxide of iron ... ... - Barium chloride ... ... - THE ANALYST. B. 0.0 4.50 , 38.55 TABLE 111. Results expressed in Parts per 100,000. Calcium chloride . . .... Calcium carbonate ... Magnesium chloride . . . Sodium chloride ... ... - I 258.55 - 20.00 - 1 100.13 I j 2039.50 C. 1.20 1.60 40.70 315.08 19.00 92.76 2093.08 D. 1.00 1.20 3.03 2.77 25.00 11 -44 215.29 The barium was estimated in the water without previous concentration by acidifying with dilute hydrochloric acid, and then precipitating with very dilute sulphuric acid (about 1 in 300) and heating to boiling. The filtrate and washings were subsequently used for the determination of the lime by precipitation with ammonium oxalate in the usual way. Having proved the absence of all other metals, including potassium, the amount of sodium oxide was ascertained, which was equivalent to the sodium chloride calculated. This was then checked by sulphating the residue from a known quantity of water, igniting and weighing, and comparing the result with the sum of the salts calculated to their respective sulphates.In this way a very fair approximation was obtained. These waters give, as I will show you, marked precipitates with potassium chromate and dilute sulphuric acid, without previous concentration. I would point out in this connection that it is not advisable, when testing waters for lead, to rely entirely upon the chromate or bichromate of potash test. This should obviously be confirmed by the use of sulphuretted hydrogen, otherwise such waters as these might be pronounced to contain lead. Thereis not very much of a striking character, from a geological point of view, to be discovered by an examination of the diagram of the section of the strata through which the bore- hole passes, and no direct evidence appears to be afforded as to the whereabouts of the barium compounds.Some of the seams are described as containing ‘( spar,’’ but I have been unable to obtain any of this for analysis, and cannot say what is its composition. Nearly one-fifth of the strata is classified under the head of sandstone, and, with millstone grit, this constitutes upwards of one-third of the whole. Clowea ( C h . News, 52, p. 194) states that the beds of the new red sandstone near Notting- And now a few words as to the possible origin of the barium salts.THE ANALYST. 71 ham are permeated by minute crystals of barium sulphate, which acts as a cementing material. Dieulafait is also stated to have shown that all primary rocks contain barium in sufficient quantity to be easily detected.The occurrence, however, of barium sulphate in the strata, although the most likely salt to be present, does not of itself account for the barium carbonate or chloride in these waters, The only explanation that occurs to me is that the barium sulphate in the rock, etc., has by some means, possibly by the action of heat in presence of carbon or carbonaceous material, been reduced to the sulphide, and this salt has then, by coming into close contact with beds of common salt or with some strong solution of brine, been converted into the chloride. This might then react with other water containing sodium carbonate, and so become changed into barium carbonate. It is possible that the carbonate might be directly produced from the sulphide, but the first hypothesis, having regard to the enormous amount of common salt associated with the barium salts, seems to me to be the more probttble.Clowes (Royal Society Proceedings, vol. xlvi.) gives the results of some analyses of deposits formed in the water-boxes of coal-mines in the neighbourhood of New- castle-upon-Tyne. These deposits consisted mainly, and in some cases almost entirely, of barium sulphate; they were soft and easily powdered, and appeared to have been produced by a process of rapid precipitation. He is of opinion that these deposits may be formed by the admixture of a water containing barium chloride, such as the one to which I have already referred, communicated by Bedson, with a water containing sulphuric acid or ferrous sulphate, produced by the oxidation of pyrites in the coal measures. The water analysed by Bedson was from a coal-mine near Newcastle-upon-Tyne.Neither Clowes nor Bedson, as far as I know, have, however, offered any explanation of the origin of the barium chloride in solution in these waters. Another instance of the occurrence of barium chloride in a natural water is to be found in a spring at Llangammarch, a, small village in Breconshire, Central Wales. This spring has been analysed by Dupr6 and by S. Arch Vasey, of the Lancet laboratory. The former found 6.26 and the latter 6.74 and 6.49 grains per gallon of barium chloride, the total mineral matter amounting to 302 grains per gallon. Waters have also been found containing this salt at collieries near Sunderland and near Rotherham, and in a spring water near Shotley Bridge in Durham. Barium chloride is said to possess valuable medicinal properties, acting chiefly upon the heart.As it is not, however, an official drug of the British Pharmacopceia, it is possible that its therapeutical effects are not yet properly understood. According to toxicological authorities, the minimum authenticated fatal doses recorded are of the carbonate 60 grains, and of the chloride 100 grains. From the results I have laid before you, it does not seem probable that cases of poisoning by the consumption of water containing salts of barium are likely to arise. DISCUSSION. The PRESIDEXT thought that it might be possible to account for the presence of the soluble barium somewhat less elaborately than in the manner suggested by Mr.White, viz., simply by the action of sodium carbonate, under pressure, on the72 THE ANALYST. barium sulphate. Without pressure, of course, the action of aqueous solutions of alkaline carbonates on barium sulphate was very slight, even when the solutions were boiled with the sulphate. I t might be, however, that the original material was barium carbonate (witherite), which would more easily be dissolved. In the red sandstone, strontium occurred as celestine, the sulphate, and as strontianite, the carbonate; and possibly barium also occurred there in the forms of sulphate and carbonate. Anyone who met with either of these waters would at once notice that there was something unusual about it, from the fact that it contained no sulphuric acid.Mr. HEHNER inquired whether the author had examined the water spectro- scopically for the presence of small quantities of strontium as well as barium. I n the case of many analyses made by Fresenius it had been demonstrated that both of these metals were often present in water, of course in very small quantities, and not in any way comparable with the cases referred to in the paper. Dr. RIDEAL remarked that an analysis made by Dr, Dupr6 of the Breconshire water referred to had been widely circulated for purposes of advertising the water as a specific for cardiac diseases; and, inasmuch as that water only contained six or seven grains of barium per gallon, it would appear that these Ilkeston waters, containing several times that quantity, should have a greater value in such diseases.It would benoted that the absence of aluminawas a characteristic feature of all these w at ers. Mr. WHITE, in reply, said that the President’s suggested explanation did not appear to account for the presence of barium chloride, and he (Mr. White) thought the barium could not exist in the water otherwise than as chloride. It might, however, account for the carbonate present in sample A, which was the original water from the borehole. The only evidence he had upon which to base his conclusion that barium sulphate was the original mineral, was the information contained in the papers of Dr. Clowes. Dr. Clowes had taken much interest in the subject, and it seemed quite clear that, in the neighbourhood referred to, there existed considerable quantities of barium sulphate in the sandstone, which formed about a fifth of the total strata passed through in boring the well; and therefore he (Mr. White) thought it fairer to conclude that barium sulphate, rather than barium carbonate, was present originally, for there was no evidence at all of the occurrence of barium carbonate in the neighbourhood. Some few miles away there was a piece of millstone grit, forced up, probably, by volcanic action, known as the ‘‘ Hemlock Stone,” from its shape and spreading top. Dr. Clowes had published an analysis of this stone, which showed that it contained in some parts a large percentage of barium sulphate. He (Mr: White) could confirm this from his own analysis of portions of the stone. He had not used the spectroscope to prove the absence of strontium, but had tested every precipitate of barium sulphate very carefully, without getting any evidence of the presence of strontium. He had no information as to the solubility of barium carbonate in solutions of alkaline chlorides, but had already, in referring to the President’s remarks, stated his reasons for assuming the original presence of barium sulphate, and the way in which he thought the chloride was to be accounted for.

ISSN:0003-2654    

DOI:10.1039/AN8992400067

出版商:RSC    

年代:1899

数据来源: RSC

摘要:

THE ANALYST. ABSTRACTS OF PAPERS PUBLISHED IN OTHER JOURNALS. 73 Testing for a Chew. Xoc., vol. xx. FOODS AND DRUGS ANALYSIS. Yellow Azo-colour in Fats, etc. A. H. Low. (Journ. Arner. [Ill, 889.)-A few C.C. of the pure filtered fat are treated with an equal volume of a mixture of strong sulphuric acid, 1 part, and glacial acetic acid 4 ,parts, the whole being then heated nearly to boiling, and thoroughly mixed by agitation. After settling, the lower stratum (mixed acids) will exhibit a strong, wine-red coloration, if the yellow azo-dye be present, whereas only a very faint brownish tinge is produced in the case of pure butter, The sulphuric acid may be replaced by strong hydrochloric acid, or a mixture of 1 part strong sulphuric acid with 3 parts water may be employed; the acetic acid mixture, however, gives the best results.c. s. The Detection of Horseflesh in Sausages. T. Baskion. (Jozmz. Pharnz. Chim., 1898, vii., 540-542.)-The author has examined various methods based on the colour reaction which the glycogen of the horseflesh gives with iodine. With the original process of Brautigam and Edelmann (ANALYST, xix., 24) he has only been able to obtain certain results in the presence of a large proportion of horseflesh, and he has also found Courlay and Coremon’s modification (ANALYST, xxi., 231) inconclusive. By varying the experimental conditions he has worked out the following modi- fication, by which, he asserts, it is possible to detect the presence of 5 per cent. of horseflesh in sausages, even in the presence of starch : About 20 grammes of the finely minced sausage are boiled for from thirty minutes to one hour with 100 C.C.of water, so that the volume of the liquid is reduced to about 30 C.C. When cold the broth is filtered, and about 10 C.C. tested with 2 or 3 drops of a solution of iodine in potassium iodide (iodine, 1 gramme ; potassium iodide, 2 grammes ; water, 100 c.c.) or of iodine water. A fugitive reddish violet coloration indicates the presence of horseflesh. The iodine reagent must be added carefully, since a slight excess changes the colour to reddish-brown. If starch is also present, the broth is decanted when cold, and from 1 to 2 volumes of acetic acid added according to the quantity of starch. After standing for 5 minutes the liquid is filtered, and 10 C.C. of the filtrate tested as before with 2 to 3 drops of the iodine solution, which in this case also produces a violet colour in the presence of horseflesh.74 THE ANALYST, Water.A summary of the author's experiments is given in the subjoined table : -.___ -- _- ____ in KI solution. Pork. I ' I 22- Starch. Water. Slight brown. Do. Ihration of Boiling. RI. Nil. Do. -- 0 i 0 i 0 ~ 40 0 1 40 0 40 Addition of 2 vols. of Acetic Acid. 1.0 F. 0 1.0B. 1'0 F. Do. Do. Reddish violet. Do. Yellowish brown. Reddish violet. Violet. Do. Do. D O . Volume of Water. C.C. 150 150 150 150 Reddish brown. Do. Reddish violet. Do. Nil. Yellowish brown. Reddish viole t. Do. Do. Do. 0 ; 20 I 0 20 0 20 'LO 0 19 1 1-OF. 0.5 F. 0.5 F. 0 0 , Reddish brown. Light brown. Dark brown. Brownish D O . 18 2 18.5 1 18 I 1 17'5 1 2 2 l7 1 0 0.5 F. 1.0 F. 0 * 5 F . 1.0 F. .- I Grammes. ' Grammes. ' Grammes 0 1 0 1 05F, I Nil. Do. Dark blue. Nil. Slight brown. Do. Dark reddish violet. Dark blue. Blood red. Reddish violet. Do. Brownish violet. Blood I red. ' Reddish violet. Do. Do. Reddish brown. Do. Violet. Reddish brown. Do. Brown- ish yellow. Do. Do. Do. 1 150 Liquid reduced to half its Do. Violet brown. Do. Do. Do. DO. Brownish 1 Nil. yellow. DO. Nil. Brownish violet. 100 150 150 150 I 150 ! 150 I Dark reddish violet. Dark blue. Reddiah brown. Faint brown. Dark brown. Do. Do. DO. Do. DO. __ B = wheat starch. F=Potato starch. C. A. M.

ISSN:0003-2654    

DOI:10.1039/AN8992400073

出版商:RSC    

年代:1899

数据来源: RSC