Usually their milk agrees excellently with infants, but there can be little doubt that asses’ milk is superior for this purpose. It is quite a mistake to imagine that it is a sufficient precaution to have a cow brought to the house and milked in one’s presence. Various expedients are known to all cowkeepers whereby the richest part of the milk can be reserved for butter making, and apart from the knowledge of physiological facts which enables this to be done, the native cowkeeper is capable of performing certain small feats of legerdemain by which the milk may be pretty freely diluted under the very eyes of his European customer. Well aware of the “sahibs’” absurd fad for cleanliness, a native cowkeeper I met with utilised our weakness in that respect to perform a very clever trick. He always brought with him a bowl of clean water, with which he ostentatiously washed the udders of the cow, and while milking, on the pretext that a cool hand was necessary for the process, he occasionally dipped his really well washed hands into the bowl. Hidden in the palm, however, was a piece of sponge, which was squeezed against the udder in the action of milking, so that its contents mingled with the milk as it jetted into the can, and by frequently repeating the cooling process, he was able to dilute the milk to a very profitable extent. It is well, therefore, to occasionally test the quality of milk, and this is better done by noting the depth of cream that rises in a given long, narrow glass, than by any of the so-called lactometers, as they really only test the specific gravity of the milk, as they afford no sure index of the amount of fatty matter present, and it is on this that the main nutritive properties of milk depends. For the use of infants on voyages, unconcentrated sterilised milk should always be used, as it is much less altered by the process than is the case with the “condensed” article, even when the latter is honestly and carefully prepared. This, however, is far from being even generally the case, as very often the milk has been skimmed before concentration, and large numbers of cases of malnutrition among infants are due to this cause, as the material lends itself easily to the perpetration of despicable frauds of this sort, which appear to be sometimes practised even by large and much advertised concerns. In the case of unconcentrated sterilised milk on the other hand, the substitution of skim milk can be detected at a glance. _Butter._--Containing as it does a considerable proportion of unaltered milk and whey, butter is open to the same dangers as the milk from which it is prepared, and it is therefore equally risky to obtain it from uncertain sources, so that, where these are doubtful, it is better to have it made in the house.