concentrated to about one-third of its original bulk. The consequence was that if the milk was diluted to the extent directed, and a child were given the amount which would be sufficient in the case of uncondensed milk, it would be half starved. He thought they should not allow these false statements and misleading directions to go unchallenged. Of course, if a case were taken into Court there was the objection that the retailer who sold the can of condensed milk was not the real author of the fraud, but ultimately the offence would come home to the manufacturer, who would find an effect on his trade; and certainly the public ought to be made aware that certain brands of condensed milk are not what they profess to be. Dr. VIETH said their best thanks were certainly due to Mr. Faber for the paper he had brought before them. They ought to congratulate themselves on the opportunity of reading in THE ANALYST the very interesting and important experiments of a foreign chemist which Mr. Faber had included in his paper, experiments which originally had been published in a language with which only very few among them were familiar. With regard to the point raised by Mr. Allen, he was of opinion that the total proteids formed the best gauge by which the degree of evaporation could be judged, the proteids being pretty constant and amounting to about 3.5 per cent. As to the mode of distinguishing between fresh milk and milk which had been heated-for this really was the point under discussion-he was of opinion that the determination of the albumen was not a suitable method. Not only was the quantity of albumen present in fresh milk very small, but the separation of the various nitrogenous bodies seemed difficult and uncertain, and the method proposed rather cumbersome. A very simple test for distinguishing between fresh and scalded milk, proposed years ago, consists in adding tincture of guaiacum, which gives a blue colour with fresh, but not with boiled milk. The reaction used to be explained by the presence of ozone in fresh milk, but Babcock, in a recent publication, ascribes it to the presence of fibrine. Mr. STOKES said that having tried various methods for complete analysis, he found none that constantly summed up to 100 on addition of the constituents. He noticed the same fact in all the complete analyses published hitherto. In regard to erroneous labelling of tins, he was afraid that no conviction would be obtained. Even in the case of a considerable number of samples prosecuted on his analysis for deficiency of fat, the magistrate held that the samples having come into the possession of the vendors soldered down, so that they could not have tampered with them, no action could lie against the vendors. The distinction between condensed and fresh milk by means of guaiacum depended upon the milk having been boiled or not. Mr. Stokes, having had charge of, and having practically worked, a vacuum-condenser, knew that often milk was condensed at a temperature not higher than when it left the cow, from 90° to 100° F.; hence the guaiacum test would in such cases fail. Dr. VOELCKER asked Mr. Faber whether he had examined any considerable number of samples of condensed milk, and if so, whether he had found each kind to be uniform in composition. In analysing a large number of one particular brand a few years ago he (Dr. Voelcker) had found great variation in different samples. He understood that for infant life especially, it was important, not only to see that sufficient food constituents were supplied when the milk was diluted, but also that the composition should be always alike. Mr. ADAMS said he quite agreed with Mr. Allen and Mr. Hehner as to the importance of not overlooking the constitution of these milks, because there was a point which had escaped remark, and that was the presence or absence of fat, a substance most necessary as a digestive agent. It was by means of the animal fat that true chyle was produced, and the albuminoids were got into the lacteals. He was convinced that a milk which had a constitution like the first of those given must be a most indigestible substance to give any animal, more especially an infant, and that was a reason why the true facts should be widely known. With regard to cane sugar in abundance, he considered it, from a medical point of view, to be injurious. Cane sugar was not easily digested, at all events by young creatures. Of all sources of complaints and disease, a very frequent one was the habit of giving children so many lollipops, and therefore he thought, in the custom of adding sugar, there was injury to the public in being misled as to the extent of dilution these milks will bear. A child must simply starve if fed on such a milk as the first one, especially if diluted to seven times its bulk. Animal fat was a most important food— in one sense more even than the albuminoids, for without fat the albuminoids could not be so well turned to their proper account. With regard to prosecutions under the Food and Drugs Act, it was a difficult point, no doubt; but he should think there was no doubt that a case of that kind could be dealt with by the law courts. Mr. ALLEN asked if a person could be convicted of selling a condensed milk when he had no hand at all in its preparation, and palpably so. Mr. ADAMS said it was similar to pickles and green peas, in which cases they had no difficulty in obtaining convictions. He did not see that that ought to be a great obstacle. Mr. STOKES said the peas contained an article injurious to health. Mr. FABER, in reply, said, that with regard to estimating soluble albumen, there was no difficulty when the amount was about 0·3 or 0.4 per cent., and if the amount of soluble albumen was so small as to be difficult to estimate, that was by itself a proof that the milk had been heated. As to the presence of fibrine in milk, he was very doubtful whether that statement would be found correct after further investigation. In reference to Mr. Stokes' remarks concerning the temperature of milk during condensation, it was quite certain you could condense milk at a low temperature, but in any case would the milk have to be heated after the closing of the tins to such a degree that the albumen was coagulated in order to sterilize the milk, and thereby ensure its keeping for any length of time? He only knew of very few analyses by this method, as it was comparatively new. ON THE QUANTITY OF VOLATILE ACIDS PRESENT IN BUTTER-FAT. BY DR. P. VIETH. (Read at the Meeting, June, 1889.) THE more precise title of my paper would be "On that quantity of volatile acids present in butter-fat which is determined when butter-fat is examined according to Reichert-Wollny's method." The results obtained find expression in the number of cubic-centimetres of deci-normal alkali required for neutralising the volatile and, in water, soluble acids. When Dr. Wollny, in 1887, published his modification of the Reichert-Meissl method for the examination of butter-fat, I in common, I believe, with a great many analysts, cherished the hope that the method would turn out an extremely useful one. Avoiding outside influences, which might interfere with the process, seemed to insure correctness, and working according to fixed and widely adopted rules, promised uniformity of results. The modified method, then, seemed to be well suited for the examination of butter-fat and the detection and quantitative determination of admixed foreign fat, provided the volatile acids present in genuine butter-fat of any origin varied within not too wide limits. According to our experience at the time, we assumed that the volatile acids yielded by 5 grms. pure butter-fat required for neutralisation from 25 to 30 c.c. deci-normal alkali solution. Since then we have learned that those limits were drawn far too narrow, that genuine butters are not unfrequently met with giving results which fall outside, more particularly below, the said limits. The more the matter is investigated, the more cases of undoubtedly genuine butter-fat containing abnormally small amounts of volatile acids are observed. My own experience with Wollny's modification of Reichert's method commences with a sample of butter-fat sent from Kiel to the members of the "International Committee," formed to investigate into the question of butter-fat analysis. I examined this sample on October 20th (a) of last year, and again on January 17th (b) and May 2nd (c) of the present year, with the following results : No. 1. Butter-fat from Kiel (a) 31.8, 316, 31.8, 319, 31.9. (b) 32.1. The insoluble acids in this sample amounted to 87.04 per cent. The agreement between the results obtained at the various occasions is satisfactory, a fact on which I wish to lay some stress, because not only was, on the several occasions, a fresh soda solution used for saponification and a fresh baryta solution for titration, but also the distilling apparatus employed for the earlier experiments had to be replaced by another one, which was of somewhat different dimensions. During the time from the middle of November to the middle of June, I applied Wollny's method in the examination of 63 samples of butter as sold in the London market. The results were as follows: With the exception of the butter manufactured in London, which was churned on the premises of the Aylesbury Dairy Company, in Bayswater, little is known as to origin and history of the foregoing samples. The results must all be considered as quite normal. The samples, of which I shall have to speak in what follows, do not refer to butter manufactured for sale. They were, moreover, prepared from small quantities of milk or cream in the laboratory under my continuous superintendence, and with exclusion of every possibility of any admixture of foreign fat taking place. The mode of proceeding was as follows:-One gallon of milk was set in a shallow pan, kept under lock for twenty-four hours, the cream taken off and churned, the butter melted, and the fat filtered. All the samples form part of a systematic investigation, which was commenced early in February and continued till the middle of May, and in one direction is still proceeding. At the end of January a brother analyst asked me for two samples of butter of undoubted genuineness. In order to put the purity entirely beyond doubt, I had two samples of cream churned into butter by shaking the cream in glass bottles. Part of the butter thus prepared I kept for examination. The one sample referred to cream produced at a butter-factory situated in Sussex; the volatile acids in the butter-fat were found to be normal. The other sample referred to cream separated on the Aylesbury Dairy Company's Farm, near Horsham, from milk produced by cows kept on the estate ; the composition of the butter-fat was to my greatest surprise quite abnormal. I determined at once to try to find out the cause for this abnormal state of affairs, and also to see whether anything similar existed with regard to milk produced on other farms at that time. First of all, another sample of cream from the butter-factory in Sussex was examined. The two samples gave the following results:- I next had small quantities of butter prepared from samples of milk received from thirty-five farms supplying the Aylesbury Dairy Company at the time. The results It will be seen that in two instances the results fell below 25; the lowest and highest figures observed were 23.9 and 324 respectively. I now come to the samples having an abnormal composition. As mentioned before, the milk from which the butter-fat in question was abstracted, was produced by cows kept on the Aylesbury Dairy Company's estate near Horsham. The following were the first results obtained : sixty head of cattle, In order to ascertain The herd which produced the milk consisted at the time of viz., thirty-nine Shorthorn, sixteen Kerry, and five Jersey cows. whether the breed had anything to do with the abnormal composition of the butter-fat, samples of Shorthorn, Kerry, and Jersey milk were examined separately. The first three samples did not show any striking difference to exist between the three breeds (see the following table), and another point was therefore taken into consideration, viz., the food. The diet of the cows consisted of suitable quantities of hay, brewers' grains, and linseed-feeding materials which enjoy a very wide application; further, of silage, on average four pounds per head per day; and oatmeal, on average six pounds per head per day. The effect of the two last-named constituents of the diet seemed to me to require elucidation; first, because silage has only since the last few years entered the list of feeding-stuffs for farm live stock; and, second, because the ration of oatmeal is much higher than usually given. After February 18th the Jerseys, and after February |