Again, the nutritive power of milk and of the preparations from milk, is very much undervalued; there is nearly as much nourishment in half a pint of milk as there is in a quarter of a lb. of meat. But this is not the whole question or nearly the whole. The main question is what the patient's stomach can assimilate or derive nourishment from, and of this the patient's stomach is the sole judge. Chemistry cannot tell this. The patients stomach must be its own chemist. The diet which will keep the healthy man healthy, will kill the sick one. The same beef which is the most nutritive of all meat and which nourishes the healthy man, is the least nourishing of all food to the sick man, whose half-dead stomach can _assimilate_ no part of it, that is, make no food out of it. On a diet of beef tea healthy men on the other hand speedily lose their strength. I have known patients live for many months without touching bread, because they could not eat bakers' bread. These were mostly country patients, but not all. Homemade bread or brown bread is a most important article of diet for many patients. The use of aperients may be entirely superseded by it. Oat cake is another. To watch for the opinions, then, which the patient's stomach gives, rather than to read "analyses of foods," is the business of all those who have to settle what the patient is to eat—perhaps the most important thing to be provided for him after the air he is to breathe. Now the medical man who sees the patient only once a day, or even only once or twice a week, cannot possibly tell this without the assistance of the patient himself, or of those who are in constant observation on the patient. The utmost the medical man can tell is whether the patient is weaker or stronger at this visit than he was at the last visit. I should, therefore, say that incomparably the most important office of the nurse after she has taken care of the patient's air, is to take care to observe the effect of his food, and report it to the medical attendant. It is quite incalculable the good that would certainly come from such _sound_ and close observation in this almost neglected branch of nursing, or the help it would give to the medical man.