The _blood_ should also be watched, and in my hospital cases I have a count made every week; for the hæmoglobin content, and the number of the erythrocytes, and the percentage of the varieties of leucocytes afford very valuable information as to the physical state of the patient, and the progress or recession of the cancer, and in a measure these data are of value in directing therapy. I have also the _weight_ of the patient taken and recorded each week, as a guide to nutrition and dietary matters. Also the _saliva_ is tested and recorded before and after each meal, and furnishes an indication in regard to the administration of alkalies. Iron is found to be greatly wanting in the blood and tissues late in cancer, and should always be an element in the treatment of this disease. Skene Keith, noticing that after a cancerous mass was removed the blood recovered in regard to hæmoglobin and erythrocytes, administered iron with arsenic, with the greatest benefit, the growth shriveling up and the patient gaining in weight; he recommends the citrate of iron and ammonia, the preparation which I have given to patients for many years past. He also advises hypodermic injections of iron, arsenic, and soda, and reports cases thus treated, some of them with good results. There is a loss of phosphates in these patients, and phosphate of iron or other phosphates are valuable. When considering the metabolism of cancer mention was made of derangement in the action of the ductless glands in this disease, and of the use and value of certain preparations of the internal secretions in its treatment. While a hormone therapy of cancer is still in its infancy, in spite of many books and innumerable journal articles on the internal secretions, it is quite possible that the future may demonstrate its efficacy in helping to control the disease: for, that the latter are efficient agents in carrying on the vital processes in the body, there can be no question, although as Biedl remarks, “Our knowledge of the chemistry of hormone formation is very slight.”