摘要:

THE ANALYST. DECEMBER, 1884. TO OUR READERS AND SUBSCRIBERS. OWING to the change of editorship, we beg to inform our readers that the following alterations will, in future, be made in the arrangement of the contentsof THE ANALYST. First in each number mill come the recoi*d of the work of that small, but admirable organisation, the Society we especially claim to represent. It will be headed Proceedings of the Society of Public Analysts,” and will, me hope, maintain in the future the high position with regard to the advancement of the Analysis of Food and Drugs, so markedly taken by British chemists since the passing of the Hale of Food and Drugs Act. At the end of such papers will come, as heretofore, the words (I Goncluaion of the Proceedings of the Society,” and for all the rest of the contents of this paper, the Society, or its officers, are in no may responsible.The remainder of the journal (for which the editor is alone responsible) will contain a record of all advances in analytical chemistry, whether British or €oreign, which the editor can collect, and in this dqartment he will be assisted by a staff of foreign correspondents. The usual system of not quoting from the other home chemical papers will not be followed, but anything interesting will be duly recorded, even if not contributed directly to our columns, as we consider that such petty jealousy is altogether unworthy of the scientific press. The matter will be arranged under the following heade :- (a) Monthly record of Analytical Researches into Food. (6) Monthly record of Analytical Researches into Drugs.( 0 ) Monthly record of General Researches in Analytical Chemistry. Following the atrictly ohemical portion of the paper, wig be found reviews of all such new works in Chemistry, or the allied sciences, as m&y be submitted by the authors or publishers. Particular attention will be paid to this department, a just opinion being earnestly sought after without fear or favour, and no undue. delay will occur in the appearance of review8. A new feature of the journal willthen be introduced, whichhas been decided upon after much careful consideration, via, an occasional record of advances or novelties in the preparation of food and drugs. Public analysts, and our readers generally, who are specially interested in the subject of food, require of all men to be placed arzl oozcralzt with what is going on in this respect, and special articles submitted by the proprietors will be referred to under this heading. Lastly, the journal will contain such legal reports as contain any novel point in the working of the Sale of Food and Drugs Act. Original articles by gentlemen, not members of the Society, will be paid for at a liberal rate of remuneration, to be ascertained on application to the Editorial Depart- ment, and members of the Society contributing papers will have a certain number of A~ALY~Ts$,o8t!edfree to such lists of friendfil as they may send in, according to the length of the article, and on this point information may alsQ be had on application a8 above.

ISSN:0003-2654    

DOI:10.1039/AN8840900213

出版商:RSC    

年代:1884

数据来源: RSC

摘要:

Ic- THE ANALYST. - 214 - SOME ANALYSES OF GINGER. BY W. C. YOUNG, F.I.C., F.C.S. Read &$ore the Society nt the meetiBg on 19th November, 1884. These aadyses were made in the hope that some data mould be found which would enable Analysts to distinguish between genuine ground ginger and that to whichTEE ANALYBT. 215 exhausted ginger had been added. realised, the constitution of the various samples being so widely different. As will be seen by the results my hope was not The samplee wei*e all well authenticated, and with the exception of thom from Malabar and Bengal, were decorticated and bleached. The aqueous and alcoholic extractions were deteimiued from a 2 per cent. and 5 per. cent. decoction respectively, both being digested for an hour under a vertical con- denser, allowed to cool and settle, the clear decoction then syphoned off and used without filtration.The cellulose was obtained by digestion, under a vertical condenser, of 50 grains of the sample, first in 16 ounces of 5 per cent. sulphuric acid, then in 12 ounces of 10 per cent. potash, and finally in water. Each digestion occupied about twenty minutes, the residue being finally collected on a filter, and thoroughly washed, dried, and weighed, then bnnit, and the ash extracted. Moisture (Loss at 1 looo C.) . L 1 Ash. a * Ash insoluble in H,O Ash soluble in H,O I Aqueous extraction (from 2"/" decoc- tion) t a Mucilage . . I Alcoholic extrac- tion (from 5°/0 decoction) Resin a * * * Cellulose * * . African 1 15.8 3.4 1 -34 2.06 24.8 18.0 8.5 2.2 5.1 - African 2 14.5 4.3 1-58 2.72 52.2 - 15.7 - - Janiaicm 15 5.4 1 -22 4.18 65.7 32.3 6.5 0.25 3.1 cochin. 15.2 5.8 328 2-52 35.1 21*8 12.5 4.5 9.0 Japan. 15.2 8.0 5.82 2.18 34.3 19-4 8.3 2-8 4-6 Malabar 10.2 3.4 1 *6 1.8 30.1 22.4 4-1 1.7 1 *7 Bengal . 20.50 4.75 2-36 2.39 51.4 41.1 4.3 0-84 4.9 DISCUSSION. After a few remarks by the chairman thanking the author for his communication this paper passed without cliscttfilsion.

ISSN:0003-2654    

DOI:10.1039/AN884090214b

出版商:RSC    

年代:1884

数据来源: RSC

摘要:

216 TRE ANALYST. ~ ~~ NOTE ON THE ADULTERATION LAW8 IN TEE DNITED STATES OF AMERICA. BY JOHN MUTER, PH.D., B.I.C. (Rend before the Soociety nt the Xoethag OIB 19th .iVoveut6ei., 1884.) 1 HAVE received a copy of the statutes that the legislature of the State of Nassachusetts has just passed with reference to the adulteration of food and drugs, and I proceed to lay an abstract of the scme before the Society, so that its members may contrast them with the law under which we are compelled to act in this country, First, as to the AdzcZteratiolz of Food.--The State Board of Health are empowered to expend, annually, an amount not exceeding ten thousand dollars, for the purpose of carrying out the provisions of this Act, provided that not less than three-fifths is expended for the enforcement of the laws against the adulteration of milk and milk products. Every person selling milk must be licensed, and his name, the number of his license, and his place of business, must be placed on each side of the conveyance used by him, or his servant, in the sale of milk.If any part of the cream has been removed, the words (( skimmed milk ” must be distinctly marked in letters not less than on0 inch in length on the outside of the vessel. Mixtures made in imitation or semblance of butter must be labelled I ( imitation butter,” or oleomargarine,” and those made in imitation of cheese muat he marked ‘‘ imitation cheese,” in bold Roman type, of notless than one half-inch in length. Milk, shown by analysis to contain more than eighty-seven per cent. of watery fluid, or to contain less than thirteen per cent.of milk solids, is deemed to be aduhrated. The terms butter ’’ and l 4 cheese ” mean the products usually known by those names, and are manufactured exclusively from milk or cream, with salt and rennet, and with or without colouring matter. The general provisions for other articles of food run as follows :-(I.) If any substance or substances have been mixed with any article of food, so as to reduce, or lower, or injuriously affect its quality or strength; (2.) I f any inferior substance or substances have been substituted wholly, or in part, for it ; (3.) If it is in imitation of, or is sold under the name of, another article; (4.) I f it consists wholly, or in part, of a diseased, decomposed, putrid, or rotten animal or vegetable substance, whether it is manufactured or n9t, or, in the case of milk, if it is the produce of a diseased animal; (5.) I€ any valuable constituent has been wholly, or in part, abstracted from it ; (6.) If it is coloured, coated, polished, or powdered, whereby damage is concealed, or if it is made to appear more valuable than it really is ; (7.) If it contains any added poisonous ingredient which may render it injurious to the health of a perc3on consuming it ; the article shall be deemed to be adulterated.Both the manufacturer and seller of any beverage adulterated with Indian cockle, vitriol, grains of paradise, opiuin, alum, capsicum, copwas, laurel water, logmood, Brazil .mood, cochineal, sugar of lead, or any other substance which is poisonous or injurious to health, are subjected to very heavy penalties.I f when sold under or by a name recogaised in the United States Pharmacopoeia, it differs from the standard Secosirl, (is to the AcZdtem5on of Dvup-The Act Bays :-(I)THE ANALYST. 21’7 of strength, quality, or purity laid down therein, unless the order calls for an article inferior to such standard, or unless such difference is made known or so appears to the purchaser at the time of such sale ; (2) If when sold under or by a name not recognised by the U.S.P., but which is found in some other Pharmacopoeia, or other standard work on moteritz medicfi, it Were materially in strength, quality, or purity laid down in such work; (3). I f its strength or purity falls below the professed atandard under which it is sold ; they shall be deemed to be adulterated.” The penalties for infringement of the provisions of the Act range from a fine of thirty dollars to an imprisonment for three yeare.The expense of the analysis is not to exceed twenty dollars (say $4) in any one case, and may be included in the cost of the prosecution. The analyst is to divide each article and retain one half sealed up, which he must deliver on application to the defendant or his attorney in case of prosecution. All this reads very nicely on paper, but in each of the sections providing for penalties the word ‘‘ knowingly ” occur^, and dnless the American attorney8 are less cute ’’ than they are taken for, it should prove as fatal to successfd prosecution as it did with us under the old Act of 1872.The chief point of interest to us as a Society is the milk standard, and it is a question whether the simple method of requiring 80 much total milk solids is after all not the simplest plan. American milk must, homepel-, be much richer thm that currently considered as a, fair average in this country. DISCUS6ION. DR. DUPRE said they were much obliged to Dr. Muter for bringing this before them; it was always well to learn what other countries were doing. He quite agreed with the proposal that if any standard was to be laid down for milk, it should be a total solid standard, irrespective of solids not fat. It was merely a matter of indifference to the man who bought the milk whether he got 3 per cent. of fat and 10 per cent. solids not fat, or 4 per cent, of fat and 9 per cent.of solids not fat, though the probability was that he might be better satisfied with the fonnex No doubt 13 per cent would be too high, but he thought about 12.5 might not be far wrong. He was quite convinced that if some standard, be it 12 or 12*5, mere adopted, all difficulties would vanish, and there mould then be practically no difference between analysts. With regard to drugs, he might perhaps lay claim to the definition as his own. He was the one who laid it down years ago, and it was almost exactly in the words in which he put it before tho Committee of tho Sooiety, which was appointed many years ago to act in the matter of drugs. He ~hould like to put in his strongest protest against the joke interpolated while reading the paper, about the American chemists being able to make a nicer analysis for four guineas than they could for 10s.6d. (Laughter.) He must say he did not think it a laughing matter. He remembered some years ago a case of adulteration of bread, where a man had certified the bread to be puye, and when it was found by another analyst to contain alum, he said, Of course, I only got 10s. foi- the walysis ; and if I had had wore I should have found ont that there was alum in the bread.’’ He (Dr.218 TEE ANALYW. Dtrpr6) could not insist upon it too strongly, especially in the presence of the younger members of the profession, that if they took an analysis in hand at all, they should do it as well as they could, whether they received one guinea or ten guineas for it.If they could not do it for one guinea, let them decline it; but if they did it, then let them do it accurately. Mr. Hehner said there was one clause he should like to see adopted in England- and that was, the division of samples by the Analysts. It was an exceedingly painful matter that the reputation of the Analysts should be placed at the mercy of the Inspectors. There were many cases of this sort. Quite lately they had a very striking case, where Mi-. Allen found a very large quantity of lead in a sample of lemonade ; whereas in the duplicate sample there was none. This duplicate sample had not been divided, but was a whole bottle; and the nemspapers of course, spoke of the incompetence of the Anztlyst. There shoidd not be any possibility of this occurring.Every sample should be divided in the presence of the Analyst, and if the Analyst mere present he mould say :-(‘I don’t want another bottle or a a whole loaf. I want part of yours.” He had often had a whole loaf brought to him, and he always felt that his reputation was more or less in the hands of the baker. He should be exceedingly sorry if Analysts were made judges of diseased or decomposed articles. I f they did so they would usurp the function which at present belonged to the Medical Officer of Health, a d Analysts were not competent to do that. He should also like to see a standard fixed for milk, but 13 per cent, solids mould be quite out of the question, 11.5 or 12 would be about it. Dr. Wynter Blyth said in criticising that Act one saw that there were some things very good and a distinct improvement upon ou19 own Act, and other things distinctly retrograde.One improvement certainly was including the costs of the analysis in the fine. That would probably have rt very good effect if introduced into our own law, because, at the liresent time, the fines were very inadequate indeed. Latterly certain London magistrates had commenced to raise the fines, but still they were seldom commensurate with the adulteration. That part of the Act as to milk was certainly good. Of course the standard solids was certainly high, a legal standard of 12 would be quite sufficient j but, if they had a legal limit fixed, it would be more simple, and would woyk veiy well, to place it simply on the totd solids and not on an37 other constituent of the milk, I t wouldbe found that the total solids in duplicate analyses fairly agreed, the differences at present found, partly arising from tohe various processes atill in existence, and partly from difference in the iimnipdation.Another retrograde movementi was the adulteration of liquors ; there were only five out of the ten substitutes mentioned which were called poisonous (exclud- ing alum) which might be really so. Even laurel water was used as a harmless flavour- ing agent, and it depended upon the quantity, whether that was poisonous; cochineal was used in temperance drinks, and was not poisonous. He could not conceive how it was that, in this 19th century, these harmless substances coulct have crept into an Act of that kind. The Analyst was to return half the sample to the Aftornq ; this would act seriously in this country, and he did not suppose people Were more honest in America.I\BE ANALYST. 219 About two years ago he had a sample of butter substituted for the one originally analysed, although the fraud was detected, and the man heavily fined ; but that sort of thing often occurred, and the Analyst was blamed unjustly. Mr.Heisch concurred on the point that it would be very much better for the Analyst to be present at the division of the sample. Analysts used to divide the samples, as they might;, perhaps, remember. From the manner in wbich samples brought to him were frequently sealed, he had a very strong feeling that if a man knowingly Bold an adulterated article, the probability was that the sample left with him would be altered.It was not at all an easy thing to seal up a sample so that it should not be tampered with, and inspectors are not cautious in their proceedings, especially when taking a milk sample in the open air-unless they get into a quiet place. Mr. Hehner said that iu the case of the butter referred to by Dr. Blyth, the sample mas sealed up in such a way that there wars no difficulty whatever in slipping apiece of genuine butter in, Dr. Dupr6 recalled the fact that in the &st sample ever referred to Somerset; House the magistrate said he was bound by their decision. It was evidently a case of a substituted sample. Dr. Muter and Mr. Wigner had portions, and they all agreed that it was adulterated, and yet Somerset Housa found theirs to be genuine. Dr.Vieth said that he knew very well that his Company had a great deal of milk with as much solids as 13 per* cent., but not all the year. They had between 900 and 1,000 samples a month, and often averaged total solids of 13%. The worst was 13.08; the March and April average was only 12.7 and 12.8, and sometimes it came down to 12. Mr. Stewart said that he remembered a cam, a good many years ago, where amilk, which they had certified .to be adulterated, was forwarded to another Analyst. Their sample was 9.8 total solids, and the other was 13. They communicated with the other Analyst, who examined the bottle which had containedthe milk mbmitted to him, and, holding it up to the light, he saw another figure on the label. He took off the label, and found another label nnder it.'when they examined their sample with this other label, they found it closely agreed with the milk submitted to the other Analyst. They afterwards found that the vendor of their milk, who lived in the same street as another milkman whose milk had been sampled, had taken the label off his own sample and gummed it on the other milkman's. He did not have the gumption to take the old label off, but actually stuck the new one over it, and then sent that sample to the other Analyst. He (Mr. Rewart) also had a sample of coffee tied up in a bag and sealed, and, by a little manipulation, he slipped the tape off, took out the sample, and put in a new one, and fastened it up again without breaking tho seal. With butters, if the Inspectors do not take the precaution when they put them in bottles to wipe the grease carefully off the neck, the cork will oome out easily.In some cases Inspectors had a small crowd round them, and then it wad not very easy to seal up samples carefully. With reference to divisions by the Analyst, or in the presence of the vendor, the old Act put everything in tho hands of the Analyst, Now it has to be divided in the-- 220 THE A.NAXYST. presence of the vendor. It seemed to him that the vendor might object to the sample being divided out of his sight just as much as the Analyst. The more reasonable thing would be for the Analyst to follow thehilector into every shop, or for the vendor to go to the laboratory and see the sample diyided ; and that was impossible. Inspectors wore generally honest, and it was pretty safe to leave it to them He did not think that any other plan would be possible, and they would have the trade complaining still more.As to the American style of the Analyst dividing the sample and sending it to thevendor, he thought the way would be for the Analyst to divide it and send it to another Analyst. With regard to what Dr. Dqr6 had said as to an Analyst doing as good an analysis €or 10s. as for ten guineas, that was very pretty in theory, but not in practice. He did not think th~ycould subscribe to that. Take a water analysis, for instance. Would Dr. Dupr6 cam to make a complete mineral analysis, with combustion, dbuminoid ammonia, and so on, for 10s. 3 DK Dqr6 said he cei4ainly gm-c the Andyst an alternatit-e plan, and if anyone came and asked hiuz to make EL water analysis for 10s. he should s h o ~ him the cloor. Mr. Ashby said that sealing was not necessary. Sealed, or otherwise secured,” were the words of the Act. For years past he had induced Inspectors to clo away with seals, they simply provic’ed themselves with lined envelopes, geiierally inscribed with the bovough a m , and the bottle of illilk or buttel- or other sample was put inside, and the Inspector wrote his signature vith an aniline pencil across the junction of the flap with the envelope. He always insisted on the use of these envelopes, and never had any difficulty with them; they even had envelopes large enough for loaves and samples of water. Dr. Muter, in closhg the discussion, said that nearly every analyst had met with instances of changed samples, but his had been by the vendors only. Ho had a milk case now pending, his sample containing under 10 per cent. solids, and the other sample nearly 13 per cent. CONCLUSION OF THE PROUEEDINGS OF THE SOCIETY OF PUBLIC ANALYSTS.

ISSN:0003-2654    

DOI:10.1039/AN8840900216

出版商:RSC    

年代:1884

数据来源: RSC

摘要:

-- 220 THE ANALYST. MONTHLY RECORD OF ANALYTICAL RESEAMHES INTO FOOD. WE are indebted to the enterprise of the Anericait Grocer Publishing Association for a very long aeries of analysis of Tea, by J. F. Geisler, of which the folloving is an abstract :- Taking the average of 6 andyses of Iudirtn tea ive find :-- Max.. mil. Average. Moisture ., .. . # 6.19 .. 6.66 .. 6.81 Half-hourExtract .. .. 39*66 .. 37*80 ., 38.17 Total Extra& . . . . 45-64 . . 41.32 . . 42.94 Insolubleleaf ., .. 63.07 ,. 48.63 . # 61.24 Tannin ., .. 18% .. 13.04 .. 14.87 Theine .. ., 3-30 ,. 1.80 .. 2% Soluble ash .. ,, 3*68 ., 3-24 .. 3*62 Insoluble ash .. ,. 2.22 ,. 1.93 ,. 2.12 AahincloI. in HCl .. .. 0296 .. -137 .. 0178THE ANALYST. 221 The average of thirteen varieties of Oolong tea yielded Max.Min. Average. Moisture . . .* . . 6-88 .. 5-09 *. 5.89 I-€alf-horu.Extraot ., ., 44.02 .. 34-10 ,* 37-88 TotalExtract .. .. 48-87 .. 40-60 ,. 43-32 Insolublcleaf ,, ,. 53.15 *. 44-80 ., 60-70 Tannin .. ,* 20.07 .. 11.93 ,. 16m38 Theine .. ., 3~50 .. 1*15 .. 2-32 Soluble ash .. .. 3*71 .. 2*60 .. 3.20 Insoluble ash ,, ,, 3.17 ,, 1’84 .. 2*68 Ash insol. in HCL , * . , -838 .. ,266 ,. *507 The czvel.tlge of eleven samples of Congou showed :- Max. Min. Average. Moisture .. . * .* 9-16 .. 7*65 ,. 8.37 Half-hourExtract .. .. 32.14 .. 23-48 ,. 28.40 TotalExtraot ,. .. 37.06 ,. 27.48 .. 34-35 Insoluble leaf .. .. 63-86 .. 54.50 .. 57.20 Tannin ., ., .. 13.89 .. 8.44 .. 11.54 Theine .. .. ,. 2.87 .. 1.70 ,, 2.37 Soluble ash ., . * .. 3.52 .. 2-25 ,, 3.06 Insoluble ash ,... 3-86 ,. 1.90 .. 2-68 Ashinsol. in HCl ,, ,. 1’31 ,. .32 .. *425 The (‘ half-hour extract ” is the result of boiling the tea for half an hour in 100 parts of distilled water, and is, in the author’s opinion, a better index of the quality of the ten than the ordinary total extract. The rest of the paper is devoted to the compari- 8on of the results of chemical analysis with commercial value, and it is shown that, although no absolutely unimpeachable ratio exists between them, yet the nearest results are got by infusing the tea for ten minutes, under b e d conditions, with 100 parts of boiling distilled water. Tables of the results so obtained are given, but as they are too long for abstraction, the reader is referred to the original article in the Amerionlz Grooe~. I n the Amhiv.der Pharmlr.cie there is a long paper on the (( Examination of Food, &a, containing Arseiiic,” by H. Beckurts.” It is an exhaustive and critical study of the different methods for the detection and estirnatiorz of arsenic in food and other organic substances. The author regards Fresenius and Babo’s method for the separation of arsenio from accompanying organic matter, by destroying the latter with hydrochloric acid and potassium chlorate, as inconvenient, and to be avoided. WGhler and Sieboldt’s method is looked upon with more favour. In this method the substance is heated with an equal weight of nitric acid in a porcelain dish, neutralised with pure potash, and, after the addition of potassium nitrate, evaporated to dryness, and ignited.The arseniate thus formed, is dissolved out by vater. Before testing the solution, however, in Marsh’ a apparatus, the nitrates and nitrites must be removed by evaporation with sulphuric acid.222 THE ANAIjYST. In criticising Schneider and Fyfe’s method, in which the arsenic is distilled out as arsenious chloride, by slowly adding sulphuric acid to a mixture of the substance to be examined with common salt, the author remarks that, of all the arsenic compounds, only arsenious acid is easily converted into arsenious chloride. The author then gives his and Herr Pehut’s researches, on a method by which arsenic compounds in organic substances can easily be determined. The substance to be examined is stirred up with hydroohloric acid (20-25 per cent.), free from arsenic, mixed with about 20 grms.of a 4 per cent. solution of ferrous chloride, and the mixture distilled froma large tubulated retort, the neck of which is directed upwards, and con- nected with a Liebig’s condensor. One-third is distilled at the rate of about 3 C.C. per minute. If the amount of arsenic present be not great, the whole of it will be in the first distillate. If larger quantities be present, the operation must, after the addition of another 100 0.0. of hydrochloric acid, be repeated. As ferrous chloride, according to Fischer, effectually prevents the volatilization of mercury, antimony, and tin in hydro- chloric acid solution, there is no fear of antimony and tin chloride being found in the distillate. The latter, after dilution, can be tested directly with Marsh’s apparatus. For quantitative determination the arsenic may be precipitated as sulphide by sulphu- retted hydrogen, or, after oxjdation, and the removal of the excess of hydrochloric acid, as ammonium-magnesium, arseniate, or, finally, volurnetrically, by titration with a standard iodine solution N.) I n this method the arsenic present as arsenious and arsenic acids distils over.Arsenious sulphide, which is often formed in putrefying organic matter containing arsenic, is also decomposed by the distillation. From the author’s quantitative experiments, the following have been a:Ilscted :- 1 . Arsenic Present tzs Arseniozts Acid-75 grms, of meat were mixed with 250 p. HCl, *01 grm. &Os and 200 0.0. 4 per cent. solution of ferrous chloride and distilled, The arsenic was determined ‘in the distillate as magnesium-ammonium arseniate : *00968 grm, A%03 was found. 2. Araefiic (GB Arsenic Act‘d.-300 gms. meat containing ai*senic acid equal to 001 gm. Aa03 were mixed with 20 gm. 4 per cmt. FeCL, and HCI 100 C.C. distilIed gave *00985 grm. As203. 3. Arsenious sulphicle was mixed with meat, and distilled as above. 42 per cent. hass was recovered from the distillate. 4. Metallic arsenic can also be easily detected even when not at all oxy&i~d.

ISSN:0003-2654    

DOI:10.1039/AN8840900220

出版商:RSC    

年代:1884

数据来源: RSC

摘要:

222 THE ANAIjYST. MONTHLY RECORD OF ANALYTICAL RESEARCHES INTO DRUGS. AT arecent meeting of the Pharmaceutical Society, Dr. John C. Thresh made a communication, on the Proximate Constituents of Hedychium Spicatum, of which the following extract embraces the chief points of ohemical interest. Preliminary trials showed that the best solvent of the active principle was petroleum etheie, the extract from this menstruum yielding a crop of crystal which when purified were found t o be tabular, colourless and odourless, soluble in petroleum ether, ether, alcohol, chloroform and benzol. Insoluble in diluted eolutions of potash, soda or ammonia, Sulphuric acid dissolved it in the cold without production of colour, but if heated theTEE ANALYEIT. 223 solution became purple red.The alcoholic solution was neutral in reaction, not coloured by ferric chloride or precipitated by basic lead acetate. It did not reduce silver ealts. Melting point 4900, Mean of two cornbustiona gave C 69*73 per wnt,, H 5.88 per cent., agreeing with formula Ola€€,,O,. By treatment with caustic potash, the cryatah yielded ethyl alcohol, and an acid yielding upon combustion 0 67.63 per cent., and H 5.69 per cent. The silver salt gave 37.55 per cent., metal. The acid therefore had formula C,oH,,O,, and the cq&dline principle CAH3C~oH90d. Upon oxidation with dilute nitric acid, anisic acid was produced in abundance, The acid therefore is methyl paraoxyphenylacrylic, an acid obtained synthetically by Perkin, by the action of acetic anhydride on anisic aldehyde in presence of sodium acetate.The Unorysta;l&~a;bls Portinn of the Petrolmm Bher ResilEzce.-This was found to consist of the odorous principle, a fixed oil and a veryconsiderable proportionof ethylmethylpmcoummte, the latter doubtless prevented from crystallizing by the presence of the former. Upon saponification of the mixture with alcoholic potash, two crysttrtlline acids were obtained, the methylparacoumaric and another, apparently a fatty acid. This latter was totally insoluble in boiling water, but cryatallizable from alcohol. The quaiitity obbined did not enable me to identify it with certainty, and its further exadnation is reserved for the immediate future. The odorous principle evidently exists in the rhizome in very minute proportion, and to isolate it in a state of purity will necessitate working on a much larger quantity of material. A very rninute quantity of the oily fluid above mentioned dropped upon the clothes renders them highIy odorous for a considerable length of time, or if esposed causes a large room to be pervaded with its odour, which to me recalls that of hyacinths.The proximate analysis of the rhizome gave the following results :- Soluble in petroleum ether- Soluble in doohol- Ethylmethyl artwownarrtte , , ~ixed oil md'odorous body . . Indif. substance ppt. by hnnin Acid resin, &c. . . . . Glucoside or sacoharine matter Mucilage.. a , .. *. Albuminoids, orpnic acid, &c. Staroh.. . . . . . . . . adoiaturo . . . . . . . . Ash a 0 * * .. Cellulose, &o... . . . . . . 1 Soluble in water- .. . . . . 3.0 . . . . . . 2*9 1 '" . . . . . . . . 2.7 . . . . . . . . 1.0 . . . . . . . . 2.8 . . . . . . . . 1*9 . . . . . . . . 62.3 . . . . . . . . 13.6 . . . . . . . . 4.6 . . . . . . . . 15.2 10090 - 'the cod-liver oil supplied to the European markets is often spuriow, being either a mixture of the genuine oil with seal or coalfish oil, or else simply the latter oils, alone or mixed, Japan also furnishes the market with so-called cod-liver oil, In order to find, if possible, a test for pure cod-liver oil, A. Eremel has made extensive experiments with oils of known origh. He determined specific gravity,224 THE ANALYST. amount of potash necessary for saponification, and amount of iodine solution necessary for iodizing the oil, but finally came to the concluaion t h t the best process for distinguishing the pure from the spurious oils may be based upon their behaviour with filming nitric acid, spec.gr. 1.500, as follows :- Ten to fifteen drops of the respective oils aze poured on match glasses, and two 01- three drops of fuming nitric acid are slowly run in from the side, when the several oils exhibit the following appearances : 1. Gemline cod-liver oil (from Gadw iliorrha) turns ~ e d at the point of contact ; when afterwards stimed with a glass rod it becomes fiery rose-red, soon passing into pure lemon yellow. 2. Coalfish oil (from Gadus Carbonarius) turns intensely b h e at the point of contact ; when stirred it turns brown, and remains so for two or t h e e hours, when it finally passes likewise into a more or less pure yellow.3. Japanese cod liver oil behaves like the preceding, except that red streaks are some- times observed along with the blue ones, on the addition of nitric acid. All three varieties likewise yield the well-known colour. reaction for biliary acids (with sulphuric aoid). 4. Seal oil, treated as above stated, at first Bhows no change of colour, and becomes brown onIy after some time. As this oil is not a liver oil, it, of course, does not give the reaction for biliary acids. According to the author, this reaction for the spurious oils with fuming nitlic acid is so intense and characteristic, that admixtures of them (of not less than about twenty-five par cent. to genuine oil) may be readily detected. Some time ago, S. G. Bradford recom- mended solution of subacetate of lead as a test for cotton oil in both cod-liver oil and in olive oil, by producing a red colour when the former oil was present.Moreover, a mixture of solution of subacet&e of lead with cod-liver oil causes saponification at omo when shaken in the cold. When cotton-seed or any other oil is present, this saponification will not take place, no matter how long the mixture is allowed to stand, or how well it is shaken. The strength of ether is almost universally judged by the test of specific gravity It is, cousoquently, of great importance that the density of absolute ether should be accurately determined. Authorities differ very much on this point. Various points ranging between 0690 aEd *720 are stated, and though some of the discrepancies may be accounted for by the different temperatures at which the estimations were made, there still lacks uniformity. In an article in the +hemera's, Dr.Squibb discusses the matter, and gives the result of a number of experiments made in order to determine the point. He acknowledges the difficulty in getting ether free from the last traces of alcohol, water, and air, and overcoming the extreme sensitiveness to heat of so volatile a fluid. His conclusions are not, so far, absolutely final, as he promises to continue his investigations when the cold weather shall have fairly set in, but for the present he gives the specific gravity at 4 C. as -73128, and at 1 5 O C. *71888 or *?I890 at 609 F. According to a table of specific gravities of various mixtures of absolute ether and alcohol of Sp. (3. *820, the official ether of the B.P., which is of the Sp. (3. -720, would contain 1 per cent. alcohol, and that of the Sp. G. 735, about 13 per cent. Dr. Squibb does not find the general statement that one volume of ether will dissolve in 10 volumesTHE ANALYST. 225 _ _ _ _ ~ - - of water to be correct. His experiments give one in 11.1 even at a temperature of 2 5 O C. Tho tests foy alcohol in ether he doea not find satisfactory. Admixture with an ecjual volume of copaiba or carbon bisulphide is not sensitive to 01 per cent., while the test with fuchsine is really not a test for alcohol at all, and for water is too sensitive for practical use. Hager’s modification of Lieben’s test is considered the best, but for very accurato dstermhations requires great care, and even then the results are not absolutely certain. In reference to Dr. Squibb’s experiments, it may be noted that absolute ether for anaxthetic purposes is commonly sold in England at a specific gravity of -717 at 60°B.

ISSN:0003-2654    

DOI:10.1039/AN8840900222

出版商:RSC    

年代:1884

数据来源: RSC

摘要:

THE ANALYST. 225 _ _ _ _ ~ - - MONTHLY REOORD OF GENERAL RESEDCHES IN ANALYTICAL CHEMISTRY. ON THE DETERMINATION OF UREA.-BY J. I?. EYlcu.N.--Rec. trav. Chimie. 3,125-136. TKE author acts upon 10 C.C. of the urea solution (containing about Q per cent.) with 50 C.C. sodium hypobromite5 C.C. Br and 150 gim. Na to the Iitre) and 10-15 C.C. sodium hydrate. The mixture is boiled until (5 C.C. have distilled over ; and the evolved nitrogen is collected in a graduated tube over mercury and sodium hydrate containing a little pyrogallic asid; the apparatus is similar to the one lwed for the estimation of nitricacid by means of ferrous oxide. According to the author's experiments, a mixture of 50 C.C. alcoholic broinine, 10 C.C. sodium hydrate, and 20 c.c. water contain 0.5 C.C. dissolved air, and he therefore deducts this amount from the observed volume of nitrogen; the urea calculated from the difEerence is too lorn, and has to be corrected by multiplying by gives 15-30 C.C.nitrogen. 100 /100.4.4L, In analysing urine, the latter must be diluted to sush a strength that 10 C.C. DETERMINATION- OF SILIUA IN IRON AND STEEL.-BY HERB VON JUPTNER.-Oesterr. Zeitschr. f. Bergu. Hiitteum. 32-559. In comnmmioatiofi from the Chemical Laboratory in Neuberg, the author gives a number of anaIyses to compare the following different methods :-( 1) Determination as raw silica (Rohkieselsrture). The iron Wngs were dissolved in strong hydrochloric acid, the solution evaporated to dryness, digested with hydrochloric acid, warmed, and after dilution, filtered, washed, dried, and weighed.(2) By fusing the raw silicawith fusing mixture of carbonates of potash and soda, anddetermininginthe ordinary way. (3) Purification of the raw silica by boiling with strong hydrochloric acid, diluting, fil- tering, and igniting. (4) By treating the weighed raw silica with hydrofluoric acid, evaporating, and weighing. The loas of weight gave the pure silica. ( 5 ) Determination by Brown and 8himer's method. The solution in nitric acid was heated, after adding an equal volume of sulphuric acid until sulphuric fumes were given off. The mean results obtained by the author me the following :-- Nethod 1 2 3 4 5 Raw Iron (HabWesXok. Essefi) 1-68 . a 1.54 .. 1*565 . . 1-50 ,. 1.61 Bessemer Plate , , . . . . 0'049 . . 0.0378 . . 0.0372 . .0.0317 . . 0'0372 The differences among fie fist three methods are easily accounted for by the specialist;. Regarding the 4th method, the reason of the results being low is that the226 THE ANALYST. impurities of the raw silicamere converted into fluorides, mhich are heavier than the corresponding oxides. The last method is especially to be recommended for cases where the manganese is also to be determined (by Volhard’s method). SEPARATION OF ARSENIC FROM TIN AND A.NTIMONY.-BY 3. HmsusMID!r.-Berichte der Chem. Qesell. 14, 1). 2 2 4 5 . T ~ ~ Author did not obtain favourable results with Fischer’s method, (Am. Chem, Pharm., 208, 128), which consists in forming the volatile arsenic tiichloride, by means of ferrous chloride, and distilling. His experiments show that much better results are obtained when the arsenic is distilled in a stream of hydrochloric acid, it being possible to separate all the arsenic in one distillation.The solution to be examined is made up to 250 C.C. with concentrated hyilrochloiic acid, and than distilled in a rapid current of the gas. The volatility of the arsenic is, however, so great that a receiver is not sufficient to retain it ; and the author has, therefore, been obliged to use a modification of Fischer’s apparatus. The receiver is connected with a Woulff’s bottle capable of holding about 900 c.c.; this is filled with either 300 - 400 C.C. of water, or an equal quantity of potash (1.2 -- 1.2 sp. gr.) To prevent overflowing, the delivery-tube, 28 cm. long and 11 rum. in diameter, which clips 10 - 15 em.into the potash. The bottle must be cooled during the operation, as it easily becomes heated. It is not necessary to distil more than 100 C.C. ; all the arsenic is then to be found in the Woulff’s bottle,. but not a ti*ace of tin or antimony. The results are equally good whether an arsenious or arsenic solution be used. The following me some of the author’s eupei.ments :- ARSENIO AND ANTIMONY. Pure metallic Antimony was oxidised with nitric acid, evaporated, and the residue, together with the arsenious acid, washed with hydrochloric acid into the distillation- flask ; the latter was then filled up to a mark, indicating 250 c.c., saturated with hydrochloric acid and distilled. Taken Found DSerenoe. As,O, .. Sb. .. A%03 .. Sb. .. h20, .. Sb. *4960 ..00743 .. 04964 .. ‘0742 .. -0004 ,. *0001 *0967 *. *3596 .. ‘0963 .. ‘3793 .. *0002 .. *003 ARSENIC AXD TIN. (rr) Assenic as Arsenious acid. Taken Found Differenw. &03 .. Sn. .. &O, .. Sn. .. A%O, .. 8 ~ . *1482 .. 01530 .. -1481 .. -1622 .. *0001 *0008 &O, .. Sn. .. Ae205 . + Sn. .* Ae205 , , Sn. ‘1040 ,. *lo60 .. *lo43 .. ‘1048 .. -0008 .. *0002 (6) Arsenic as Axsenic acid. A TEST FOR ARSEXIC.--~~Y H. Hmm.-pharm. centralhalle, xxv. No. 45, p. 537.- IF a small quantity of a solution of sodium thiosulphate be added to a hy&*ochloric aoid solution of arsenic, a yellow precipitate of A+ S3 is obtained. In this way theTHE ANALYST. 227 arsenic can be detached in a solution of 1/16w dilution. The formation of the arsenic sulphide is assured if to 3-5 C.C.of the arsenic solution 2-5 drops of the sodium thio- sulpbate be added. By warming (to 80"-90" 0.) it may be obtained free from, or with very little, sulphur, so that its yellow colour is not hidden. QUANTITATIVE ANALYSIS BY ELEBTROLYSIS.-~N the latest number of the Beriohte dw Bwrlimw Chemischelz Gw.ZZsehaft is a long and interesting paper by Alex. Classen on Electrolytic Quantitative Analysis. The author first describes the process in general; and gives a number of methods for the separation and estimation of the different metals. A short abstract of the paper will doubt- less be interesting to English readers; for the author maintains (B.314. 2771) that the methods are simple and rapid, and allow of even greater accuracy than the ordinary gravimetric ones.The batteries used are either galvanic cells (Meidinger, Leclanch6, or Daniel's) or thermo-electric elements. The Meidinger, which supplies a constant current for a considerable time, can only be used in isolated cases, such as the precipitation of copper, bismuth, and cadmium, as the current is too weak for a quantitative separation of most metala from their double oxalates. The negative electrode, on which the precipitation takes place, is a thin platiaum dish, weighing about 35-37 grms. 19 cui. in diameter, 4.2 cm. deep, and holding abont 225 C.C. water. It is absolutely essential that the dish be perfectly clean and free from fat before use; or else the precipitated metal wilI not adhere to it. Dishes which have, in course of time, become rough and scratched cannot be used.DETERMINATION OF COPPER AND CADMIUM. These inetals are separated out quantitatively from their double ammonium oxalate salts, To obtain a sufficiently weak current two Bunsen elements, in compound circuit (so as to act like one cell), are used. Froin 10-12 hours are required Tor the separation of about 0.15 grrn. Cu or Cd. The end of the reaction may be detected by testing a drop of the copper solution with a fresh solution of potassium ferrocyanide. SEPARATION OF COPPER FROM IRON. The author used iron-alum and cupric sulphate in his experiments. To the solution of the two salts ammonium oxdate is added in excess ; it is then electrolized as above, To determine the iron in the solution free from copper, a few grammes of ammonium ovalate are added, and the solution electrolized with two Bunsen cells, Copper is separated from nickel, cobalt, magnesium, aluminium and phosphoric acid in the same way.DETERXINATION OF ANTI MBNP, Antimony can be precipitated in the metallic state from a cold solution, containing ammonium sulphido in c~ccss. Sundry slight precautions have, however, to be taken ; the ammonia sdphide must contain neither free ammonia nor polysulphides ; and the antimony must not exceed 0.2 grm. To ascertain whether. the reaction be complete, the dish is tilted so that the liquid comes into contact with a fresh surface of platinum j if, after a quarter of an hour, the surface still remain clean the antimony is all precipitated,228 THE ANALYST. DETXRMIXATION OF TIN. To the neutral solution, ammonium sulphide is added, it is then conaiderably diluted with water and electrolized with two Bunsen cells.DETERMINATION OF PLATINUM. The platinum salt; is dightly acidulated with sulphuric or hydrochloric acid (or ammonium oxalate is added), and electrolized while gently warming. It is best to use only one Bunsen cell, for the separation takes place too rapidly with two. The author adds that the inaccuracy of the determination of potassium as potassium platinic chloride is notorious ; and therefore proposes for accurate determinations of potassium, ammonium and nitrogen the precipitation of platinum by electrolysis of the double salts, especially as its separation requires less time than that requisite for drying the platinum compounds. SEPARATION OF FRON COBALT. To determine both metals, the solution of the double oxalates is electrolized by Bunsen’s elements. A few c.c of a potassium oxalate solution (1.3) are added, and, according to the quantity of the substance taken, 2-4 grms. ammonium oxalate ; the whole is then warmed and electrolized. The operation requires from 3-5 hours. The iron and cobalt having been weighed together, they are dissolved in dilute sdphuric acid, and the iron titrated with permanganate solution. To compensate for the colour of the cobalt sulphate, nickel sulphate is added. Iron and nickel are determined in the same may. By electrolysis of the double oxalates. The results are only good when the zinc is less than one-third of the iron; for if more be present, it re.%ssolves. The author gives a large number of results which have been obtained, With the elecholytic methods, in his laboratory ; to judge from these, the process certainly deserves all the praise he bestows upon it. SEPARATION OF IRON FROM ZINC. F. H. H. Bonn, 2 1 st November.

ISSN:0003-2654    

DOI:10.1039/AN8840900225

出版商:RSC    

年代:1884

数据来源: RSC

摘要:

228 THE ANALYST. CURIOSITIES IN FOOD ANALYSIS. AN esteemed correspondent (F.R.S.) has forwarded to us a copy of the Internationaf Health Exhibition Randbook on I‘ Public Health Laboratory Work.” He specially calls our attention to the portion on, ‘‘ The Work of the Hygienic Laboratory,” by Dr. Corfield and Mr. Charles E. Cassal, F.I.C., P.C.S., and freely expresses his opinion thereon. We do not publish his letter or all the extracts he has suggested, because the latter are too lengthy and the former is somewhat strong. We, however, reprint from the work some annotated paragraphs for the delectation of our readers, who may not have advanced so far towards perfection in analytical chemistry as the authors of the work. In doing so Re have taken the liberty of using italics to emphasize the lessons conveyed, and me trust that what is meant as instruction will not be made a matter of amusement, or carped at by wicked scientists like our correspondent :-'THE ANALY8T.229 Expense 320 o2iject it8 a.ltalgsis, and ability $0 emiZy Zgt from 60 to 180 lbs., a useficl paliJication.--" The volume of a good-sized bottle of from two t o six liires capacity, and provided with a well-fitting stopper, may be taken by carefully filling it with mercury and then measuring the volume of the mercury by pouring it into a glass measure." (Page 54.) Advances in the Chemistry of Arsenic.-" If a very large quantity of air containing arsenic be drawn through a tube heated to redness by a gas flame, a 'metallic mirror,' or ring of nzetaZlic arsenic will be formed in the tube, which is recognizable by its peculiar crystalline structure and by other tests." (Page 60.) A peal@ definite standard f o r water a€ last.-" It should be clearly understood that in all these processes it is necessary to adopt certain standards for guidance.In the case of albuminoid or organic ammonia, for example, the limit 0.1 5 parts per million, meaning thereby 0.15 parts of ammonia (grammes, ounces, &c.), yielded on distillation by one million parts (grammes, ounces, &c.) of water, has been &xed upon as the result of experience. Pure water, known to be uncontaminated, not yielding more than this amount, and polluted waters fiat yielding less." (Page 68.) Arc addition to our previous& Jnowtc Poisons.--" The metals which may be present in drinking-water, and which have to bo considered as regards their poisonous action are lead, copper and iron." (Page 69.) Iite?+esting facts about .iMilli Analysis and striking instmwe of O r p i c Coinbustioiz in really competent hands.--" For example, the chief proximate constituents of milk are : Water, fat, caseine, milk, sugar, mineral matter (including common salt and phosphate of lime) ; the principal zcltimate constituents being the elements oxygen, hydrogen, carbon, nitrogen, calcium, phosphorus, sodium and chlorine.The isola- tion on the determination of the respective total quantities of the $timate con- stituents of such a substance as milk is a cowqarathely easy matter, but we do not thereby obtain cery much information as to its value as a food, or as to the purity or non-purity of a particular sample of it, such information being rather obtained by a atudy of its proximate constituents." way of talcilg Fat i~ NiZk.-(' A weighed quantity of the substance, which may.previously require some preparation as in the case of milk, ikom which the Zryer part of the water must firat be removed, is digested with ether at the boiling tem- perature of that liquid. A really scientific way of estimnthg alcohot, to say nothhg of its practical cofivenienzce, espcciaZZy i~ SzGm?iw.--" The distillate having been received in a flask, fitted air-tight to the end of the condenser, is made up to the same volume as the volume of liquid experimented on (100 C.C. or more, as the case may be) with distilled water. The specsc gravity of this distillate at 0' c. (32" Pahenheit) is then accurately taken in a specific gravity flask." Here we willstop (the number seven being a strictly orthodox one), and we trust (Pfiges 71 and 72.) (Page 74.) (Page 78.) that this introduction of a little of the light literature of science may not be distaateful to our readers. As to the bearing of all this up00 the proposal to conatitute this ' 4 Hygienic Laboratory ') in pmpetuity, me ahall have some words to say in an early issue,

ISSN:0003-2654    

DOI:10.1039/AN8840900228

出版商:RSC    

年代:1884

数据来源: RSC

摘要:

250 THE ANALYST. REVIEWS. A COURSE OF QUALITATIVE CHEMICAL ALALYSIS. By the late T. G. Valtwtin, revised and corrected by V. R. Ho@&imot&, Ph.D., and A: H. C h a p w ~ . London : J. and A. ChWChill. IN the former Editions of Talentin’s Qualitative Analysis the undoubted value of the book was obscured for general students, by the exceedingly copious use of constitu- tionalformulm In the present edition this drawback has been modified to a great extent, and the formdm and equations given are such as to be easily grasped by any ordinary student. There can be no doubt of the care with which Messrs. Hodgkinson and Chapman have done their work, and on careful perusal we have been struck by the freedom from wrata, and from the unreliable reactions too often introduced in such works.The acid course is extremely good, and is a real one, worthy of the name of a course, and the preliminary examination with sulphuric acid, so impor.ant from a practi- cal point of view, is fully entered into. We also find special instiwctions for the analysis of insoluble cyanogen compounds and silicates. The general poition of the book occupies 240 pages, and following that ve have 43 pages devoted to the rare metals, and the whole concludes with a set of illustrations of spectra. To tjum up the merits of the book in a single sentence, we say that it is one of the best works of English origin on the subject of general mineral Qualitative Analysis at present before the public, and does its present revisers the utmost credit. When the constitional fonnuh (which are really out of place in a strictly practical book) are altogether removed, it will become all that can be desired.TULETS 03 Cm&ircfi hziLp8rs. By Armattd Xempls, B.A. London : BailliAre’s EP is a, great pity that the compiling of theso tablets was not left by the proprietors of the (( Students’ Aids Series” in the hands of a practical analytical chemist. We do not cloubt that following the course laid down for bases, the student may eventually come to the right conclusion, but the same effect might be produced in an infinitely more simple manner. Take, for instance, the second gro~p, and keeping in remembrance the fact &at the book only deals with one base and one acid, we have a direction to distinguish B g from Bi and Cu by the action of boiling hydrochloric acid on the group pre- cipitate (if black), involving, of course, filtration and washing.Then, again, although PbS is specidly mentioned as a possible constituent of the precipitate, we have no conhnation for lead given. Now, it appears to us, that any practical analyst getting a blaok with 31,s insoluble in N&ES would simply take a little of the original solution and settle at once whether it was Pb by adding a drop of diluts H,SO, and then finish the affair by the action of ICHO to distinguish between Hg, Bi and Cu in a manner which we advise the author to try. Again, in the third group, the examiners who want to catch a man crammed upon these tablets, have only to give him calcium phosphate and upset the whole affair. The acid courm is wisely not called a course in (( steps ” but in ‘ 4 trials,” and it mould be there the candidate’s ‘( trials ” would, in our opinion, begin.There are no directions for the proper preparation of the solution 80 necessary before acid terjting, and the very first (‘ trial ” vith AgNO, l a d s the unhappy student ( 4 Students’ ‘Aids Series.”THE ANALYST. 231 is a maze of fifteen possible acids. It is astonishing that with so many real acid courses at his hand in other works, the author should not have adopted one of them where the abseuce of certain acids are properly assured, and all those capable of giving odours or appearances with B280a are first of all put out of the question or readily detected and specially confirmed in the original solution. We are sorry to be unable to commend this portion of the 8eries.b a TO PUBLIU €IEA,LTH, By J. L. T. Z’hzcdiehztm, ZD. London : Bailliere’s Students’ Aids Series.” THIS is an addition to a set of cram books, very justIy popular among medical students. That anything more than the merest sketch of the subject could be given within the compass of 50 short pages is of course absurd, but what is done is well and tersely expressed. In a word, the book is more an index to what to read than an actual work on the subject. As such it mill doubtless sell and fulfil its mission. THE ASSAY AND ANALYSIS OF IRON AND ,STEEL, IRON ORES AND FUEL. By Thomas Bayleg, London : Emmott and Co., and E. and IT must at once be admitted that this is an exceedingly tnseful little book, as it gives the pure and simple processes well and shortly described, and divested of undue verbiage.The matter it contains mas originally contributed by the author to the Medanical World, but is now extended and improved. The system is to give in large type the process for each determination as tested and approved by the author, and then to add, in smaller characters, all those processes which have from time to time been published by other workem in the same line, That, although in small compass, the work is really an exhaustive monograph, mill be at once apparent when we state that, commencing with the preparation of the specially pure reagents required for such work, it takes us through the estimation of manganese, phosphorus, silicon, sulphur, graphite, tungsten, carbon, chromium, titanium, slag, oxygen, nitrogen, &a, all in iron and steel.It then deals with iron ores, and finally, with the analysis of fuel. There are found a compendious set of recent analyses of such typical steels as those used by IGxpp, by the Russians, the Swedes, and in our own Royal Gun Factories, not to mention the products of Landore and the British Iron Go. There are fifteen illustrations, and in a word, the subject is well exhausted. This book will be found a very useful one by all interested in the impoi-tant industry with mhich it deals. THE ALELALI-MAXERS’ POCKET-BOOK. By 6. finge, Ph.D., and F. Aicrter, PkB. THIS book is the outcome of Dr. hnge’s work, under the auspicee of the Committee, formed some time ago, by the German Alkali-Makers’ Society, to decide upon fixed pro- cesses, specific gravity tables, and standards generally, to be recommended for universal use by all the members in the analysis and valuation of the various chemicals with which they deal.It is, as it were, the first attempt at the establishment of a manufacturers’ pharmacopoeia, intended to hold good until officially revised at a future date. Only one definite process is selected in each case, and no question of choice or detail is left to the Aztthor of “ A Pocket Book for Chen~i‘sts.” F. N. Spon. London : George Bell 8t Sons, York Street, Covent Garden.232 THE ANALYST. judgment of individuals. Conimencing with 70 pages of useful tables, the book devotes a similar space to the analysis of such articles as fuel, pyrites, salt cake, manganese ore, limestone, lime, bleaoliing powder, potassium ohlorate, black ash, soda, ash, nitrate of Boda, chloride and sulphate of potash, gas liquor, ammonium sulphate, furnace gases, gtc, ; concluding with rules for sampling and for making standard solutions. I t is a work which must of necessity find a place on the shelves of every chemist dealing with the subject.

ISSN:0003-2654    

DOI:10.1039/AN8840900230

出版商:RSC    

年代:1884

数据来源: RSC

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232 THE ANALYST. C 0 R R ESP OND EN C‘E. [The Editor is not in any way responsible for opinions expressed by his Correspondents.) To THE EDITOR OF c c T ~ ~ ANALYST.” SIR,-I can bear witness to the ferroc anide test for zinc spoken of by Mr. Allen in thia month’s ANALYST, having used it for some years. $ believe it was shewn me by a friend, who had come across i t in testing a water for iron. 1 am in the habit of applying it directly to the water in the presence of excess of hydrochloric acid, and I believe it is slightly more sensitive in this form than where chloride of ammonium is used in a neutral solution. A solution of zinc was prepared, containing one part in 200,000, with five per cent. of ammonium chloride; after half a minute or so a cloud appeared, the solution was then divided into two parts, and to one of them a little hydrochloric acid was added ; after a further interval it was observed that the latter solution was distinctly the more turbid.On one occasion, having peroxydized iron with pemanganate before using the ferrocyanide test for that metal, I ObBerved, after a short time, a white cloud, which I afterwards found was due to manganese. Since the appearance of Mr. Allen’s paper, I have further investigated this reaction, and b d that in a five per cent solution of chlorideof ammonium it is extraordinarily delicate, astrong and immediate turbidity appearing in solutions.of manganese containing only one part per million. I do not find this test, which seems to be of much value as a negative one, in any of the text-books. Since making my experiments I have looked back through my file of the ChemicaZ Newi? to the original paper of Mr.Allen, and I find that there he mentions ferrocyanide as a test for manganese, but the precipitate in that caee is a ooloured one, and he gives no data as to delicacy. I think, therefore, that my observation is worth recording. Yours, $0.’ Shrewsbury, November 8th, 1884. THOMASP. BLUNT. To TEE EDITOR OF “TRE ANALYST.” SIR,--In the extract on the L c Determination of Arsenic,” given in THE ANAZYBT for November, In the example given the amount of As, 0,’ taken for the experiment, is stated to be 0.1814 p., If, as would appear, the iodine solution were decinormal, the corresponding amount of As,O, The 38-9 0.0. iodine solution is given as equal to 0.1323 gmn., oompared with 0.1330 required by %culating the arsenic the quantities would be 0*1458 Aa.found and 0.1374 required by theory, there is evidently a misprint, and the amount of iodine solution required for the final titration is given as 38.9 C.C. would be 9.1925 grm., theory requiring 0.1814. the0 Southampton, November loth, 1884. I: am, yours, &c., J. BRIERLEY. To THE EDITOR OF “TEE ANALYST.” SIa,-Having in the practice of my profession observed that exhibitors of unpatented inventions, a t International and Industrial Exhibitions, are not generally aware that their position is affected by certain provisions of the c 4 Patents, Designs, and Trade Harks Act, 1883.” I beg to point out through the medium of your paper that the six months’ protection of Inventions so exhibited is no longer accorded unconditionally, such protection being now obtainable only b compliance with the requirements stated in Section 39 of the above mentioned Act, and Rule 17 of the Jatents Rules.Details of the mode of procedure may be obtained from the proper official souroet of information, without charge, on application. I am, Sir, your obedient servant, W. T. WHITEMAN, Fellow of the Institute of Patent Agents. BOOKS, &c., RECEIVED. Aids to Public Health, by J. L. W. Thudichum ; The Assay and Analysis of Iron and Steel, by Thomas Bayley; Inorganic Chemistry, by B’rankland and Japp; Report (forty-secmd) of the Legislature of Massachusetts relating to the Registry, edited. by Frank Wells, N.D. ; Statutes of Massa- ohusetts, relative to the adulteration of Food and Drugs ; Tablets of Chemical Analysis, by Armand Semple ; American Druggidi; The American Garden ; American Grocer ; The Brewers Guardian ; British Amercan Journal ; The Chemist and Dru gist ; The Cowkeeper and Dairyman’s Journal ; The Grocer ; The Grooers’ Gazette; Independent Journa?; Invention and Inventors’ Mart; The Lancet ; The Medical Becord ; Medical Press and Circular ; The Pharmaceutical Journal ; Ban Francisco News &etter ; Science Monthly ; Scientific American.

ISSN:0003-2654    

DOI:10.1039/AN8840900232

出版商:RSC    

年代:1884

数据来源: RSC