The question of adopting a fixed standard for all natural products is one that has been widely discussed. It would have the advantage of simplifying the issue to be decided by the analyst and of preventing possible errors of judgment in the case of samples upon the border line between undoubtedly genuine and undoubtedly adulterated products. On the other hand, the legal fixing of a standard gives security to a skilful adulterator, who is able to make his goods fall within the limit of the figures given by genuine products of low quality. Although most of the milk in large towns consists of the mixed products of many herds of cows, and thus tends to have a percentage of fat only slightly higher than that required by the law, there is but little doubt that a considerable proportion is scientifically watered and thus brought down to a limit of richness, which is only a little above that which will enable it to pose as milk straight from the cow. Another instance of this effect of standardisation was seen in Bavaria, where a few years ago a minimum analytical figure was fixed for lard, with the result that the American lard merchants sent to Germany large quantities of lard which answered the requirements of this test, but were heavily adulterated with beef fat. However much an analyst may deprecate the fixing of standards for such products as milk and butter, he is forced in practice to fix a standard for himself. The Society of Public Analysts, recognising this, passed a resolution that milk to be regarded as genuine must contain not less than 11-1/2 per cent. of solid matter, and of this not less than 3 per cent. must be fat. This fixes the standard for milk at a very low limit, and undoubtedly leaves a margin for the watering of rich milks. On the other hand, Dr. Vieth, whose experience in the examination of milks was probably unequalled, wrote in reference to this standard: "I think it is very judiciously fixed, but in upholding the standard of purity, it should never be forgotten that the cows have never been asked for nor have given their assent to it, and that they will at times produce milk below standard. A bad season for haymaking is, in my experience, almost invariably followed by a particularly low depression in the quality of the milk towards the end of the winter. Should the winter be of unusual severity and length, the depression will be still more marked. Long spells of cold and wet, as well as of heat and drought, during the time when cows are kept on pasture, also unfavourably influence the quality and, I may add, the quantity of milk." Mr. H. D. Richmond, who had also had the opportunity of examining an immense number of samples of milk, considered that the standard of 3 per cent. of fat was a reasonable one for the mixed milk of a whole herd, but considered that milk ought not to be pronounced as watered unless the solids other than fat were well below 8·0 per cent., except upon evidence derived from other tests.