Milk tends, however, to undergo changes spontaneously, which produce its coagulation, and the occurrence of these changes is greatly favoured by a moderately high temperature, such as that which exists in the stomach. But the alterations of the fluid that accompany this spontaneous coagulation are very different from those which are brought about by the vital processes of digestion. An acid becomes formed within it, and the acid thus produced has none of the solvent power of gastric juice, but by its presence impedes rather than favours digestion. Every nurse is aware that a very slight acidity of the milk will suffice to give an infant vomiting, stomach ache, and diarrh[oe]a, and the result must be much the same whether fermentation had begun in the milk before it was swallowed, or whether it commences afterwards, in consequence of the disordered condition of the stomach, and the absence of a healthy secretion of gastric juice. The nature of the food is the first point that requires attention in the management of these cases of infantile dyspepsia. If the child had been fed on cow's milk the symptoms may be due to the gastric juice not having been able to dissolve the curd, which you will remember is much firmer than that of human milk as well as twice as abundant. In this case the substitution of asses' milk, the employing whey either entirely or in part instead of milk, and the adding white of egg in order to present the elements of the curd in a more easily digestible form, may all be tried with advantage. Sometimes children refuse whey; and then a mixture of cream and veal broth, more or less diluted either with water or with the white decoction, may be given instead. The addition of soda, potash, chalk or lime water to milk before it is given is also of service, since it not only prevents the occurrence of fermentation, but also renders the curd of cow's milk more easily soluble. The indiscriminate and over-free employment of these alkalies, however, as nursery remedies is by all means to be avoided, for the symptoms of indigestion for which a grown person if suffering would seek the advice of a skilful doctor require his help no less when the patient is a child. When acids will be of service in promoting the secretion of the gastric juice, when pepsine will be likely to be of use, when stimulants such as a little brandy, when aromatics to get rid of flatulence, opiates to relieve pain or check diarrh[oe]a, or when an occasional mercurial, or some other remedy may be of use by stimulating the liver to increased action, are questions which I would not advise any mother to try to answer for herself. Much care and pains and knowledge and experience are often required by the doctor to enable him to answer them correctly.