THE ANALYST. AUGUST, 1881. 141 SOCIETY OF PUBLIC ANALYSTS. AN EXTRAORDINARY GENERAL MEETING was held at Burlington House on the 27th June; the President, Mr. Heisch, in the chair, for the purpose of considering the desirability of giving power to the Council to nominate Foreign Members for election by ballot. It was proposed by Mr. Wigner, Secretary, seconded by Mr. Lyte, Secretary, that the following be inserted in the Rules of the Society at page 2, line 5 from top, after "personal knowledge": "Except in the case of any candidate not residing in Great Britain or Ireland, in which case a majority of two-thirds of the Council present at any meeting may recommend the candidate to the Society for election." The motion was put to the meeting and carried unanimously. A Special Meeting was then held. The minutes of the meeting held on 1st June were read and confirmed. The following gentlemen were proposed as members, and will be ballotted for at the country meeting:-Mr. C. Girard, Public Analyst for Paris, and Mr. C. T. Kingzett, Analytical Chemist, F.C.S., F.I.C. Mr. Heisch read a further paper "On the Swedish Laws for the Sale of Poisons." Dr. Wallace sent for inspection by the members of the Society a Certificate by the Government Chemist at Stockholm, of a test for Arsenic in a carpet, together with the tube containing the result of the test, and a piece of the carpet. This certificate had been translated, and a copy of the translation will be found on another page. The following papers were also read: "On the Figures or Patterns which Drops of various Fats assume under certain Conditions," by A. Wynter-Blyth, M.R.C.S. "On the Estimation of Quinine in Wines, Tinctures, &c.," by A. Wynter-Blyth, M.R.C.S. "On a Modification of Wynter-Blyth's Apparatus for Digestions in Ether, as applied to Milk Analysis," by W. F. K. Stock, F.C.S., F.I.C. "On a New Burner for Griffin's Gas Muffle Furnace," by W. F. K. Stock, F.C.S., F.I.C. "Note on the Determination of Nitrogen as Nitrates," by S. Harvey, F.C.S. "On the Detection of Lead in Waters by Potassium Bichromate," by S. Harvey, F.C.S. NOTE ON THE ISOLATION OF STRYCHNINE. By ALFRED H. ALLEN. Read before the Society of Public Analysts, on 11th March, 1881. CHEMISTS who are in the habit of employing ether and chloroform for the separation of alkaloids and other active principles from aqueous liquids, will have noticed a marked difference in their behaviour. In the case of ether, the layer of solvent either separates in a few seconds from the aqueous liquid, or can be induced to do so with absolute certainty by adding more ether or by thoroughly cooling the liquid. I have never met with an instance in which ether refused to separate very rapidly, provided that it was used in such quantity that the etherial layer fully equalled in bulk the lower aqueous stratum. The behaviour of chloroform exhibits a great contrast with that of ether; frequently many hours, and occasionally days, being requisite for its separation from the aqueous layer, and for the coalescence of the chloroform globules. Even then it not unfrequently has a milky appearance, which is rarely if ever noticed in the case of ether. Some operators by preference employ chloroform rather than ether in cases where either liquid is equally suitable, as it is in the isolation of quinine. This preference is probably generally due to the supposed advantage obtained by the greater density of chloroform, which causes its collection below instead of at the surface of the aqueous layer. In certain other cases, however, there is the far stronger reason that chloroform is a greatly superior solvent for the substance to be extracted. Strychnine forms a notable instance of this, being variously stated to require from 340 to 1800 parts of ether, but only 7 to 10 parts of chloroform for solution. Nevertheless, and doubtless in consequence of the trouble and delay in the separation of a chloroformic layer, Dr. Tidy and other eminent toxicologists recommend the use of ether instead of chloroform for the isolation of strychnine. I have myself, till lately, been in the habit of employing ether for the same reason, but now use a solvent which unites a high solvent power for strychnine with the property of ready separation from the aqueous liquid. This consists of a mixture of equal volumes of chloroform and ether. Such a mixture has a density of about 1.10, and hence is sensibly heavier than most aqueous liquids. I have however, recently employed it with solutions so largely loaded with sugar that the solvent mixture floated on the surface; nevertheless, the separation occurred with great facility. In cases where the aqueous liquid approximates very closely in gravity to the solvent, separation can be readily induced by adding water (or better, ammonia). Of course, an additional quantity of chloroform or ether may also be added, but if the former be employed in notable excess the facility of separation is apt to be materially impaired, whilst if ether be added in considerable quantity the solvent power of the mixture for strychnine is materially reduced. That this last objection, however, has no great weight is proved by the following results of experiments made by my pupil, Mr. Charles Harrison, to test the point. One gramme of commercial strychnine was dissolved in acidulated water, and the solution diluted to 100 c.c. Experiment I.-10 c.c. measure of the above solution (= 100 gramme strychnine) was treated with excess of ammonia, and the liquid agitated with 10 c.c. of a mixture of equal bulks of chloroform and ether. On drawing off and evaporating the solvent, exactly 100 gramme residue was obtained. On again agitating the alkaline liquid with ether-chloroform, an additional weight of 004 gramme was extracted. Experiment II.-A repetition of the above experiment gave 087 gramme by the first extraction, and an additional 019 gramme on re-agitating, thus making a total of 106 gramme dissolved. These experiments sufficiently prove that the solubility of recently precipitated strychnine in ether-chloroform is amply sufficient to ensure its solution in practice. It will be observed that the weights of the total residues obtained somewhat exceeded the original weights of the alkaloid employed. This fact is doubtless due to the strychnine as dried for a short time at 100° C., retaining some water of combination. I propose to examine this matter more fully. It was found that when the solution of the strychnine in ether-chloroform approached dryness, it was exceedingly apt to decrepitate, thus occasioning loss of alkaloid. This tendency was avoided by adding a few drops of alcohol towards the close of the evaporation. This precaution is only necessary when perfectly pure strychnine is in solution. The small quantity of impurity usually extracted along with the strychnine when the method is used in toxicological investigations, appears to prevent the tendency to decrepitation. In the extraction of strychnine in such practice, I find it convenient to bring the acidulated aqueous liquid to a volume of about 20 c.c., agitate it with ether-chloroform to remove piperine, glucosides, &c., separate, render the liquid strongly alkaline with ammonia, and at once agitate with 30 c.c. of ether-chloroform. The separation usually occurs very rapidly, but may be induced with certainty by adding water or ether in the manner already described. ON THE SWEDISH LAWS FOR THE SALE OF POISONS. Read before the Society of Public Analysts, on 27th June, 1881. You will remember that when I brought before you an abstract of the Swedish decrees on the sale of poisons, I drew your attention to the fact that, though the production of a brown or black arsenical mirror in a tube of 2 m.m. diameter, from 50 Swedish square inches of paper hangings, or 25 of textile fabrics was said to be enough to prohibit the sale of such goods, no hint was given as to the process by which such mirror was to be produced, nor of the quantity of arsenic it was supposed to represent. Since that time I have endeavoured to determine what is the smallest quantity of arsenic which will produce such a mirror, and as no process was mentioned, I used what I thought the best, the modification of Marsh's test, in which the arseniuretted hydrogen is passed through a red hot tube, and the arsenical mirror produced in the tube just beyond the red hot portion. I place before you three tubes. No. 1, diameter -inch, contains arsenic from 001 gr. AS,O,. No. 2, 1-inch diameter, arsenic from 00116 ASO,, the same amount of arsenic as No. 1. No. 3, one-tenth inch diameter, the same amount of arsenic. Even this last is one-fifth larger than the Swedish tube, yet the arsenical mirror is absolutely opaque. How much farther one could go I cannot quite say, but half the above quantity gives not only a perceptible mirror, but when sublimed on to a micro-slide a good crop of octahedral crystal of AS,O,. The only difference I can find in the results from AS,O, and AS,O, is that while 001 AS,O, is all reduced and deposited in half-an-hour, 001 AS,O, takes over two hours for complete reduction. Professor Sell, of Stockholm, when asked what process was intended by the decree of November, 1879, replied that he could not say any particular process was ordained, but he should treat the sample with either H2SO,, or fuming nitric acid, wash and precipitate with HS, and reduce with NA,CO, and KCy. This would certainly not give such good results with small quantities as the Marsh test, and take much more time and trouble. 5 A few days since we received from Dr. Wallace, of Glasgow, for exhibition to-night, a sample of carpet which had been condemned by the analyst in Stockholm, with the certificate and tube of arsenic attached, as directed by the act. A translation of this certificate I place before you, the parts in ordinary type being the official printing, those in italics the filling in for this particular article. On the certificate is the description of the process employed, which is much that contained in Professor Sell's letter, but more detailed. Dr. Wallace also gives us the process as described to him by the owner of the carpet, which is the same as that on the certificate, with this addition, that the fact of the mirror being enough to condemn the carpet was judged by observing if a black line on a white ground could be seen through it: if it could not the sale of the article was prohibited I may mention that according to the best evidence we have been able to obtain, no injurious effects have yet been traced to a paper hanging containing as little as 5 grains per piece of nine square yards, but beyond this it is not safe to go. This would correspond to ⚫001 grain in 16 square inches, and from that quantity we can, as you see, obtain an opaque mirror. In Sweden 50 Swedish square inches or 68 English are employed, and an opaque mirror condemns the article. If, however, the process mentioned on the certificate shown be universally employed, probably much larger quantities would be required to produce the same mirror as we obtain by Marsh from 001 grain. Dr. Wallace mentions that he cannot obtain satisfactory results by following the Swedish method, at which I think no one will be surprised. You will observe that on the certificate the fee, 3-50 is mentioned as the official one. This means 3 krona 50 öre, or 3 krona and a-half, the value of the krona is 1/1, so the fee is 3/91. This beats our adulteration fee hollow, but I suppose money goes farther in Stockholm. BUREAU OF TECHNICAL CHEMISTRY, STOCKHOLM, 40, DROTTINJGATTEN (QUEEN STREET), 40. At the Bureau of Technical Chemistry was left on the 8th instant by Messrs. H. I. Heymann & Co., of Gothenburg, a sample of so called tapestry carpet of various colours, the remainder of which is attached hereto. That according to the present poison regulations, the trade in the same is forbidden. The glass tube attached hereto is that in which the arsenical mirror was received. The examination was carried out by breaking up the sample with fuming nitric acid and washing the mass with water, precipitating the heavy metals with sulphuretted hydrogen after concentration. Treating the precipitated sulphides with caustic ammonia, evaporating the solution so obtained to dryness, and reducing the residue with soda and cyanide of potassium in a stream of carbonic acid on the Von Babo-Fresenius method. All the reagents used have been found by me free from arsenic, which I hereby declare. Trades Chemist in Stockholm, Reference No. 7521. A. WERNER CRONQUIST. Analysis No. 30,170. Fee according to prescribed tariff, 3-50. The following is the mode of testing for arsenic in textile fabrics, &c., by the Swedish |