Upon the basis of a careful diagnosis, the necessary nutritive salts or cell-foods, carefully compounded in accordance with the law of chemotaxis must be administered. This law discovered by _Engelmann_, requires that these cell-foods must be administered in digestible and assimilable forms so that the cells will be attracted by the chemical reaction, which may be of a positive or a negative character. This being so, we can easily build up the tissues, by studying their chemical composition and supplying to the system that which is necessary, in the form of food. The cell will take care of the rest. Each tissue has its specific cell-system, and each cell will be attracted only by those ingredients which are needed for the mother tissue. _To bring to a tissue through the blood the lacking constituent element or elements is the only means of regenerating and healing diseased cells._ In this connection we are considering only constitutional diseases. It has been shown that the lack of certain chemical elements from the blood signifies disease and that the variety of the disease depends on which of the elements are either lacking entirely or are present in incorrect proportion. After this lack has been determined, the course to pursue in curing the disease is to supply the lacking chemical elements in the form of concentrated cell-food in _addition_ to the regular food. This method displaces entirely the old system of filling the body with poisonous drugs in order to _counteract the effects of the disease_. Such a system may suppress the symptoms by benumbing the nerves and preventing pain, it may counteract the natural process of healing of which inflammation, fever and pain, are the outward manifestations;--_but it can never cure_. The discovery of dysaemia, or impaired blood supply, as the governing cause of disease, has destroyed another idol of modern fetish worship in medicine. Since the discovery of various species of bacilli, which accompany nearly every form of disease in some form or other, these have been commonly declared to be the causes of diseases, and the tendency is to find some poison that will kill the bacilli in order to cure the disease. The bacillus, on the contrary, is only the consequence, or symptom, of a disease. The diseased and decomposing parts furnish fertile soil suitable to the propagating of bacilli because of the lack of the normal chemical elements in the blood and tissue. But to kill them, while the underlying conditions for their reproduction remain unchanged, can, obviously, never effect a cure. So the great hopes that have attached to sero-therapy are doomed to disappointment, and the application of anti-toxins prepared from the serum of animals, are fated shortly to vanish in the wake of others of those strange temporary crazes which periodically obsess mankind for a while and pass away.