THE ANALYST. 34 1 BRITISH ASSOCIATION MEETING. The following are abstracts of two papers read at the Meeting in Dublin, and will be found of interest to our readers :- MILK ADULTERATION. BY E. H. COOE, 3.8~. SINCE the introduction of the Adulteration Act, the services of the public analyst had been most frequently called in to decide the question of the adulteration of milk; and he feared they must add that more unsatisfactory decisions were given than in other proBecutions. Instances had occurred in which innocent milk sellers had been fined for selling a pure article, and in many cases they might be sure the fraudulent dealer had gone unpunished.I n his own experience he had found a difference of as much as 18 per cent., and Dr. Voelcker had published analyses in which as great a differewe as 25 per cent.occurred. -4s a result of four years’ experience on this subject, it appeared to Mr. Cook t h d milk was subject to a variation owing to the food, a variation owing to the season, a variation owing to the animal, and a variation owing to health. The best milk was given by those cows which were fed on grass, and the better the grass (other things equa1) the richer the milk.That the quantity of milk yielded by the same cow varied at different seasons of the year was well known, and the quality also varied considerably. Generally speaking, milk was richer in summer because the milk-producing articlcs were thhn available for food. Some cows gave better milk than others, which might be due to some individual peculiarity of the animal or to the breed.Guernsey was the best breed for qudity combined with quantity. Devons produced milk rich in fat but were inferior t o Guernseys. Herefords were good useful cows, as also were Shorthorns; but the first place must be given to Guernseys. Their milk is richer in solids and in fat, and the butter is of a finer colour. The course adopted by most analysts was to take as their standard the lowest percentage of solids or of 4 4 solids not fat” which pure milk had ever been found to contain; but this was open to objections.By tho Adulteration Act the analyst was to fix the percentage himself, and it varied. I n order that justice might be done, fraud detected, and the dignity of the chemist maintained, it was necessary to remedy that unsatisfactory state of things. Only one method appeared to offer a chance of success, Briefly, that was to buy and sell milk by quality instead of by quantity.One method of introducing the practice would be to divide the milk into two qualities, first and seconll, the former to include all milkE containing 12 per cent. of solids, or 9 per cent. Milk was a substance which varied greatly in quality.34 2 THE ANALYST.of “ solids not fat,” and to be sold, say, at 4d. per quart, and the latter t o include milks containing less than 12 per cent. of solids, or 9 per cent. of solids not fat,” and t o be sold at a lesser price. The vendor thus selling according t o the quality, no unjust prosecution could arise. Some efficient instrument, however, should be put into the hands of farmers and others, so that a rough analysis might be made, and the milk sold on the results o’btained. This system, the author thought, would tend to stop adulteration, because it would no longer pay t o adulterate, a better price being got for the better articles, and it would tend to put an end to those colnplaints of medical men, who, after advising their patients to take milk, found its effect so uncertain and unsatisfactory.ON THE ADULTERATION OF DRUGS. BY CEARLES R. 0. TICHBOXNE, LL.D. THE author stated that in his paper he should not refer t o the adulteration of the expensive drugs and chemicals such as saffron, scammony, quinia, nitrate of silver, which no douht did occur ; but a few recent experiences vould illustrate the fact that adulteration is perhaps even more extensively carried on with cheap drugs than dear ones.H e had been informed on good authority that powdered hematite-red iron ore- is frequently sold as the peroxide of iron. It is still a favourite remedy, particularly among amateur doctors; and as the Pharmacopceial article is only worth a few pence per lb., a vaiiable rock with various proportions of oxide of iron-I0 t o 70 per cent,- should not be eubstituted for it.He was not, however, prepared to vouch for the eorrcctness of this statement from actual observation ; but the following instances had come under his own immediate notice :- ( ( Phosphorus and nitric acid,” he said, ‘( are not very dear substances, and thcrefore we would suppose that a preparation like phosphoric acid would always be made, as directed from those chemicals, particularly when sold as the B.P. acid; but I place before you a specimen of the so-called 3. P. acid which is made from bone-ash and oil of vitiiol, On reference t o Watts’ ‘ Dictionary of Chemistry,’ vol. iv., pages 500 and 644, it is there stated that a Yery pure acid may be obtained by treating bone-ash with oil of vitriol, repeated treatment with H,SO,, evaporation, and other manipulations not necessary to specify in this paper.The writer says, after describing the process, ‘ The filtrate, when boiled, constitutes a solution of ortho-phosphoric acid, contaminated with B trace of sodium, but otherwise pure.’ Now, whether it is possible to remove the whole of the lime and magnesia by easy and cheap means I am not prepared to say.But, as far as I can see, the sample of so-called phosphoric acid under examination more exactly represents the biphosphate of lime of the manure-makers than the Pharmacopceial acid. I t gave a voluminous precipitate on adding chloride of ammonium and carbonate of ammonia, and a l ~ o contained appreciable quantities of magnesium. Here we have a chemical product cheap in itself, cheap a8 regards the sources from which it is procured, and yet sold impure.The doctors’ dose-30 drops-is not much, and yet it must be cheapened for the commercial greed. ( ( Linseed is n Terg cheap commodity, owing partial17 t o the extensive cultiyation of the plant for flax and other putposes, and also because, as regards the seed, we utilise the whole of the residue after expressing the oil.After getting the latter yalualleTHE ANALYST. 343 product we have the linseed cake, also Faluable as a cattle feeder, which, when ground, is prized by the medical man for its emollient properties. Well may the plant be called Linum usitatissinaum. Of such universal application is this substance that it becomes important that we should have it extremely pure and free from extraneous matter.Yct even the cheapness of this commodity has not saved it from the adulterator’s handd. Extensively as it is pressed for oil, grapes are much more extensively pressed for winc and, unfortunately, the wine-grower cannot utilise the produce of his wine-press except for manuring his vineyard ; therefore the wine-press residue may be practically considered as a dead loss.Hut one ingenous wine-grower bethought himself that, as he had a press, it was only necessary to add a little linseed farina t o grape residue to produce a very presentable linseed cake, as far as the eye went. I show you now specimens of linseed cake manufactured abroad, in which the residue of the grape, stones and stalks, can be easily recognised by a very low power of the microscope.” Now the Pharma- copaeia describes colocynth as ( L the dried decorticated fruit freed from the seeds.” A colocynth apple had been found to be thus composed- Professor Tichborne next showed three mmples of colocynth.Per cent. ... Seeds (inert) ... ... ... ... .,. 47.19 Rind (nearly inert) ...... I . , ... ... 33-78 Pulp ... ... . # . . I , ... ... ... 19.03 So that, taking Meissner’s analysis, which states that the pulp only contains 14 per cent. of colocgnthin, we have- Per cent. of active principle, Pure sample ... ... I.. ... . a . ... 14.3 Turkey pulp ground without removing seeds .., ... ... 4.2 Colocynth ground with rind and seeds ... ... ... 2 G Of three samples shown to the Conference, Professor Tichborne said all were obtained in commerce. ( ( One is a sample of the very best average quality, but dill containing a very large proportion of seed ; in fact, it is very seldom without indications of the presence of that substance, and I believe it is generally the practice to powder the colocgnthin pulp with the seeds remaining in it. The second sample is one which is much darker in colour, and consists of the whole colocynthin apple ground. The third sample is not only the whole colocynth ground up, but a sufficient quantity of potato starch, added to make the colour light-as well as being a profitable transaction. A medical man, indeed, prescribing 8 grains of such a powder, would be disappointed in the results.” 100~00