Various diseases, the description of which will be found in other sections of this work, affect the nervous system to a greater or less extent--for example, ergotism, lead poisoning, uremia, parturient apoplexy, colic, and other affections associated with cramps, or spasms, etc. Disease of the ovaries or of the spinal cord, by reflex irritation, may cause estromania (see "Excess of venereal desire," p. 148, constant desire for the bull). DISEASES OF THE URINARY ORGANS. By JAMES LAW, F. R. C. V. S., _Formerly Professor of Veterinary Science, etc., in Cornell University._ Of the materials that have served their purpose in building up the animal body or in sustaining the body temperature, and that are now to be thrown out as waste, the greater part is expelled from the system through the lungs and the kidneys, but the agents that pass out by either of these two channels differ in the main from those passing by the other. Thus from the lungs in the form of dioxid of carbon--the same gas that comes from burning of coal or oil--there escapes most of the waste material resulting from the destruction in the system of fats, sugars, starch, and such other foods as are wanting in the element nitrogen, and do not form fibrous tissues, but go mainly to support animal heat or maintain functional activity. From the kidneys, on the other hand, are thrown out the waste products resulting from the destruction of the foods and tissues containing nitrogen--of, for instance, albumin, fibrin, gluten, casein, gelatin, woody tissue, etc. While much of the waste material containing nitrogen leaves the body by the bowels, this is virtually only such of the albuminoid food as has failed to be fully digested and absorbed; this has never formed a true constituent part of the body itself or of the blood, but is so much waste food, like that which has come to the table and again carried away unused. If the albuminoid food element has entered the blood, whether or not it has been built up into a constituent part of the structure of the body, its waste products, which contain nitrogen, are in the main expelled through the kidneys, so that the latter become the principal channels for the expulsion of all nitrogen-containing waste.