It is understood, I trust, that I believe that for the proper treatment of cancer, and to prevent its occurrence and recurrence, it is absolutely necessary to maintain a perfect vegetarian diet, which includes even the exclusion of eggs and milk, with food; but the yolk of eggs may sometimes be taken with advantage, and also milk alone and separate, at a body temperature, one hour before eating, according to the plan which I have often demonstrated to you. As remarked in my last lecture, the vegetable kingdom contains proteid sufficient for the system, and the diet should be so arranged as to give the requisite quantity of calories, in proper proportion, of vegetable protein, carbohydrates, and fats: the latter is accomplished largely with butter, of which a quarter of a pound may be taken daily. Many writers on diet hold that the protein in casein acts differently from that contained in meat, and this is allowed in many vegetarian dietaries: it also contains phosphorus, which is an integral part of living cells, especially their nuclei. When nutrition seems to demand it, this can, perhaps, be added to the diet, mixed with cereals or in soups, and a small amount of certain kinds of cheese is also sometimes allowable. It is impossible to elaborate the details of diet fully in a lecture such as this, and I must refer you to the many excellent works on food and nutrition (Hutchinson, Sherman, Thompson, Buttner, Braithwaite), for further information. The _medical treatment of cancer_ patients is a matter which should receive most careful and constant attention; indeed, the patient in whom cancer is threatening or has developed should be under the watchful and unremitting guidance of a physician who grasps the importance of the matter and is prepared to guard the health, and to meet and correct functional disorders as they arise; for a careful study of patients with cancer for many years has constantly shown me gross errors in their life and in the action of various organs, and consequently disorders of metabolism which are of weight in connection with the disease.