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salicylic acid could be detected and separated with perfect certainty from matters containing it, and the same was true of benzoic acid. As to boracic acid, he congratulated
, Mr. Cassal on bringing before them so ready a method of estimating it. The method, though not strictly original, was little known to the majority of analysts.
Mr. Allen said he sympathised with any analyst who acted the part of pioneer. With regard to what had been said as to consultation with brother analysts before taking any decided action, he might remind them that the Society had not met for a period of five months, which was an undesirably long time. He thought the paper and comments on it showed the great value the Society had for its members.
MR. Adams said that no better illustration could be given of the value of their meetings than that afforded by the papers just read by Messrs. Hehner and Cassal, and the remarks of the members present that had thereby been elicited ; in all cases where a question arose such as these papers brought forward, it was a good thing that the views of the profession as a body could be ascertained, in order that some unanimity of action might follow, and mutual support and confidence fostered when circumstances necessitated new lines of action in reference to the official duties of the public analyst.
His own opinion with reference to the point at issue was that Mr. Cassal had used rather too strong a term when he said " poisonous"; but although boracic acid may not be poisonous in a general sense it did not follow that it may not sometimes be injurious -its effect probably might vary, and depend very much upon the individuals operated upon. It was well known that some drugs which act favourably on most people, seriously disagree with others, and even in ordinary matters of food it was astonishing what a variety of opinions were held by various people regarding the wholesomeness and digestibility of various food substances. He himself knew of a remarkable case of a gentleman who always suffered in a surprising manner after eating mutton- this food which is commonly regarded as being particularly easy of digestion, acted upon him as a violent poison-causing him to vomit, and to be purged ; at first it was set down to some mistake or fancy on his part, but no, let the mutton be disguised in any way by mixture with other things, or by the addition of condiments, the same result always followed its ingestion, so that one might contend that it was impossible to predicate with certainty that any particular food or drug would be equally acceptable to all persons. In the speaker's opinion, therefore, in every case of preserved food it should be stated that such and such a food was preserved by the addition of salicylic acid or what not, so that the consumer might know what he was about to use. Moreover, ho did not think any substance should be admitted into general use until its innocence had been established, until then it should be looked upon as an injurious, if not poisonous substance, and he thought this seemed to be the general opinion of the members of the society present.
Dr. Veita said that he was very strongly of opinion that, so far as the London trade was concerned, there was no reason why fresh milk and cream should contain boracic acid, the best proof being that large quantities were sold daily to which no preservative had been added. But if someone went to any grocer's, poulterer's, cheesemonger's, or other shop, asking for potted cream which was expected to keep sweet for several days, and if that cream was found to contain boracic acid, he-Dr. Veith-must maintain that such cream certainly was of the nature, substance, and quality of the article demanded.
Mr. Cassal said that the case which had been alluded to by Mr. Hehner was one in which he had certified a milk as having had at least 30 per cent. of the original fat abstracted, and as containing boracic acid. The authority had, therefore, not prosecuted on that point alone, but it was a part of the complaint as stated in their sum
The case was heard at petty sessions, and he was informed that the Chairman of the bench of magistrates in convicting the defendant severely reprimanded him, and made some strong remarks about the boracic acid adulteration. He certainly considered it most desirable that the public analysts of the country should fully discuss all matters of this kind, and that they should be as far as possible agreed. Squabbles between professional men in a law court were most injurious and discreditable. Public analysts did not act sufficiently in concert, and this was still one of the great evils of the profession, although matters were now much better than they used to be in this respect. But it was not always possible to consult one's colleagues, or to get a particular subject adequately discussed and a definite decision arrived at. It was plainly the public analyst's duty to certify milk containing boracic acid as adulterated. He could not act other. wise. The public authority who received the certificate might or might not take action
This was no part of the analyst's business. If they took action he could not stand in the way of their doing so. He hoped that the Society would arrive at some decision in the matter.
Mr. HEHNER said that he had not the remotest intention to express any censure upon Mr. Cassal for having taken action against a vendor of preserved food; on the contrary, he was thoroughly in accord with Mr. Cassal's opinion. But after public analysts had allowed, and almost encouraged, the use of food preservatives for many years—their open sale was no secret—it was rather hard now to suddenly turn round and to say to the dealers, "you have added a poisonous or injurious ingredient to the
, food you sold.” As in the case which he mentioned in the beginning of his paper, there was abstraction of cream, the magistrate naturally did hold that this was aggravated by the addition of preservatives. He thought it would be desirable to select, as a test case, one in which no ordinary adulteration had been practised, such as the addition of boric acid to cream, or to otherwise genuine milk.
In his opinion, the injuriousness and otherwise of antiseptics was altogether beside the question. Granted that in at least 99 per cent. of food preservatives did no harm, the addition being unnecessary, was illegal under the Sale of Food Act. It should not be forgotten that in the process of digestion, bacterial organisms, especially in the lower portions of the intestines, played an important part in helping to break up such food matters as had escaped solution by gastric and pancreatic ferments. Food preservatives were added with the avowed object to prevent the growth of bacterial organisms, but we had a perfect right to object against the destruction of our intestinal bacteria, which, in all probability, were necessary aids to our nutrition, by our milkmen, buttermen, butchers and brewers.
Dr. Adams had alluded to the fact that certain persons might be affected by some preservatives, whilst others were not. In our ordinary feeding we all know this to be
If a person, for instance, from his experience knew that pork disagreed with him, he naturally would avoid eating it. But if a person were more or less affected by boric acid or other preservatives, how could he avoid it, as it was presented to him in so many articles of food without any notice whatever ?
(Conclusion of the Society's Proceedings.)
BY T. C. VAN NUYS AND R. E. LYONS. Tuat albuminous bodies are completely precipitated from solution by tannic acid is proven by the investigations of Liborius, Girgensohnt, Sebeliens, and others. By * “ American Chemical Journal."
† Beitrag zu quant. Eiweissbestimmungen. Dorpat, 1871. | Beiträge zur Albuminometrie. Dorpat, 1872. § Studien über die analyt. Bestimmungsweise der Eiweisskörper mit besonderer Rücksicht auf die Milch.
Sebelien's method of estimating the total quantity of albuminous bodies in milk, 3 to 5 grams. milk is diluted with some water, a few drops of a solution of sodium chloride or magnesium sulphate added, and the fluid is then treated with an excess of Almén's solution of tannic acid,* the precipitate filtered off, well washed, and the nitrogen in the precipitate estimated by Kjeldahl's method.
The weight of nitrogen is multiplied by 6.37, the product of which is the weight of albuminous bodies in the weight of the milk taken. The factor 6:37 is the number of times the per cent. (15:7) of the nitrogen in albumen is contained in 100
Sebelien's method differs from the methods of Almén and Liborius in not depending on the fixed constitution of the compound of albumen and tannic acid, but rather all of the albumen is separated from solution, and that all nitrogen compounds not albuminous can be removed from the precipitate by washing.
Our studies of this subject were carried on with the view of ascertaining if a method of estimating albuminous bodies in urine, employing tannic acid, is practical. As urine contains nitrogenous compounds in considerable quantities, the tannic acid compound of albumen is not easily washed until pure; besides, by continued contact of an acid, or acid salts, uric acid is precipitated, which would remain in part with the albumen ; and as the volumetric method of estimating albumen with tannic acid has not been found accuratet, if there remains a practical method for estimating albumen in urine with tannic acid, it is that the total quantity of nitrogen in albuminous urine is first estimated, following which estimation is made of the quantity of nitrogen in the urine having its albumen separated by means of tannic acid. The difference in the quantities of nitrogen found is the weight of nitrogen of the albumen, which multiplied by 6:37, would give the weight of albumen. To determine if the method here outlined yields . accurate results, the question arises if uric acid or other nitrogenous compounds of normal urine are retained by the precipitate formed by the tannic acid and albumen when filtered, so that the volume of urine in the undiluted filtrate would contain a smaller quantity of the normal nitrogenous constituents of the urine than is in a corresponding volume of urine before the separation of albumen.
To determine this we estimated the nitrogen in normal urine before and after the introduction and removal of known quantities of albumen. We determined if Almén's solution of tannic acid produces a separation of any part of the nitrogenous compounds of normal urine, or of urine containing an abnormal quantity of the urates, and finally we employed the new method and the gravimetric method in estimating the albumen in urine and compared the results.
Pure albumen was prepared by dissolving the whites of eggs in a small quantity of water, saturating the solution with magnesium sulphate and filtering. The filtrate was then treated with dilute acetic acid until a precipitate ceased to form, filtered off, and the precipitate washed with a saturated solution of magnesium sulphate.
* 4 grams. tannic acid, 8 c.c. acetic acid (1 part glacial acetic acid and 3 parts water), 190 c.c. dilute alcohol, 50 per cent.
† Beiträge zur Albuminometrie von Girgensohn; Dorpat, 1872. Einige Methode zur Werthsbestimmungen der Milch von Tarazewiscz ; Dorpat, 1873.
Having pressed the precipitate between porous paper, it was dissolved in a small quantity of water, the solution neutralised with sodium hydrate, and dialysed until nearly all of the magnesium sulphate was seperated. To the turbid solution of albumen a small quantity of the oil of thyme was added to prevent bacterial decomposition, and having mixed well, the solution was filtered. In case a solution was too dilute it was concentrated by evaporation at 40° to 50° C., and when nearly free of ash, some sodium chloride was added to facilitate the precipitation with tannic acid. Solutions of ovalbumen we number 1, 2, 3, etc.
FIRST ALBUMEN SOLUTION.
Estimation of Albumen. (1). 10 c.c. albumen solution, 10 c.c. water mixed. (a). 5 c.c. of the solution required by Kjedahl's method 47.3 c.c. } normal KOH.
(6). 5 c.c. of the solution required by Kjeldahl's method 47•3 c.c. } normal KOH, corresponding to 0·1512 gram. nitrogen in 100 c.c of the undiluted solution of albumen.
(2). 10 c.c. albumen solution, 10 c.c. Almén's solution of tannic acid mixed and filtered without dilution.
(a). 5 c.c. of the filtrate required by Kjeldahl's method 49.9 c.c. } normal KOH.
(6). 5 c.c. of the filtrate required by Kjeldahl's method 49 95 c.c. } normal KOH, average 49.925 c.c., corresponding to 0.0084 gram. nitrogen of bodies not albuminous in 100 c.c. of the albumen solution, The quantity of nitrogen of bodies not albuminous deducted from the total quantity of nitrogen, 0.1512 gram. leaves 0.1428 gram. nitrogen of albumen, corresponding to 0.90963 gram. albumen in 100 c.c.
(a). 5 c.c. of the diluted urine required by Kjeldahl's method 3.58 c.c. } normal KOH.
(6). 5 c.c. of the diluted urine required by Kjeldahl's method 35.8 c.c.normal KOH, corresponding to 1.5904 gram. nitrogen in 100 c.c. of the undiluted urine.
(2). 20 c.c. urine, 10 c.c. albumen solution, 10 c.c. Almén's solution of tannic acid, mixed well in a small flask, and filtered without diluting.
(a). 5 c.c. of the filtrate required by Kjedahl's method 35-75 c.c.} normal KOH.
(6). 5 c.c. of the filtrate required by Kjeldabl's method 35-8 c.c.} normal KOH, average 35.77 c.c., corresponding to 1.5932 gram. nitrogen in 100 c.c. of the undiluted urine; but as there was 0.0084 gram. nitrogen in 100 c.c. of the albumen solution which was not of the albumen, and therefore not precipitated by tannic acid, and the volume of No. 2, 5 c.c. is 1 albumen solution, there is of 0.0084, 0·0021 gram, nitrogen bodies not albuminous of the urine, and consequently 1.5932
0 0021 = 1:5911 gram. nitrogen in 100 c.c. urine. Therefore there was a gain of 0.0007 gram. nitrogen by the process, 1.5911 – 1.5904 = 0.0007.
SECOND ALBUMEN SOLUTION.
Estimation of Albumen. (1). 10 c.c. albumen solution, 10 c.c. water. (a). 5 c.c, of the diluted solution required 47.9 c.c. } normal KOH.
(6). 5 c.c. of the diluted solution required 48:0 c.c. } normal KOH, average 47.95 c.c., corresponding to 0.2296 gram. nitrogen in 100 c.c. of the undiluted albumen solution.
(2). 10 c.c. albumen solution, 5 c.c. Almén's solution, 5 c.c. water, mixed well in a small flask and filtered.
(a). 5 c.c. of the undiluted filtrate required 49.95 c.c. } normal KOH.
(6). 5 c.c. of the undiluted filtrate required 49.95 c.c. } normal KOH, corresponding to 0.0056 gram. nitrogen of bodies not albuminous in 100 c.c. of the undiluted albumen solution. Deducting the latter weight from the weight of the total quantity of nitrogen (0.2296 - 0.0056 = 0.224), there is 0.224 gram, nitrogen of the albumen in 100 c.c. of the solution, which corresponds to 1.42688 gram. albumen in 100 c.c. (0.224 x 6.37 1.42688).
(6). 5 c.c. of the diluted urine required 37-35 c.c. } normal KOH, average 37-325 c.c., corresponding to 1.4196 gram, nitrogen in 100 c.c. of the undiluted urine.
(2). 10 c.c. urine, 5 c.c. Almén's solution, 5 c.c. water, mixed well in a small flask and filtered.
(a). 5 c.c. of the filtrate required 37.25 c.c. } normal KOH.
(6). 5 c.c. of the filtrate required 37.3 c.c. } normal KOH, average 37-275 c.c., corresponding to 1.4252 gram, nitrogen in 100 c.c. undiluted urine.
Deducting of 0.0056 gram., the weight of nitrogen of bodies not albuminous, there remains 1:4238 gram. nitrogen in 100 c.c. of the undiluted urine. The results show a gain of 0.0042 gram. nitrogen in 100 c.c. of the undiluted urine after the separation of the albumen, 1.4238 — 1.4196 = 0.0042.
(To be continued.)
REPORT OF RECENT RESEARCHES AND IMPROVEMENTS IN
ANALYTICAL PROCESSES. On Coco Nuts. L. van ITALLIE. (Ned. Tydschr. v. Pharmacie). October, 1890.A large nut contained about 155 grammes, of milky fluid of 1,022 specific gravity (at 18° C.) The reaction was faintly acid, and no precipitate was obtained on boiling or on addition of acetic or picric acids, showing the practical absence of albumenoids, which might have been expected in a so-called milk. 100 c.c. of the Auid were evaporated to & syrupy consistence and extracted with alcohol. The precipitate was washed on the filter with alcohol, but it readily dissolved in a little water. Delicate tests showed no traces of albumen, but the liquid readily reduced Fehling's solution. The filtrate was evaporated to a very small bulk, once more treated with alcohol, and the precipitate finally dissolved in water. The solution was not precipitated by picric acid, Mayer's solution, phospho-tungstic acid, potassium-cadmium iodide, platinic chloride, auric chloride, and tannic acid. Neither lead acetate nor the basic salt gave any precipitate, and no alkaloidal or glucosidal body was extracted by agitation with ether, chloroform, or benzol. 280 grammes of the endocarp were grated and pressed out. The fluid was precipitated with lead acetate, and the filtrate treated with liquor plumbi. The