Several authorities besides Jeandelize have attributed tetany to alterations of the parathyroids: for instance, Pineles; and at the German Congress of Medicine in Munich, Erdheim communicated his observations in three cases of tetany, in each of which, at the post-mortem, there was found hypertrophy of the parathyroids. Dr. Macallum, of Johns Hopkins University, has also reported the case of a person who developed tetany in consequence of a dilatation of the stomach, and in whom the parathyroids were found to be hypertrophied. We learn from the foregoing that the parathyroids protect us against poisons that arise from the stagnation of the contents of the stomach, and that their integrity is necessary as a safeguard against important alterations of the nervous system. However, these glands, which were already described by Sandström twenty-two years ago, have not been studied as yet to the same extent as the thyroid, and we cannot enlarge further on this subject at the present time. ------------------------------------------------------------------------ CHAPTER XII. HYGIENE OF THE THYROID GLAND. THE rational hygiene of the thyroid gland consists in the avoidance of all agencies that may prove harmful to the gland, the most important of which are infectious diseases; frequent pregnancies; sexual excesses; intoxications by food, stimulants, or drugs; and emotions such as grief, sorrow, etc. It will not be difficult to prevent some of these, but it will be nearly impossible to avoid others, such, for instance, as infectious diseases. There is not the least doubt, however, that at times we expose ourselves quite unnecessarily to infections, as when we drink water that has not been boiled or filtered, or when we take milk from uninspected dairies for a long time; or, again, when we remain too long a time in the confined air of assembly halls, etc., and breathe the air that has been exhaled by thousands of others, many of them possibly with infectious diseases of the throat and lungs. Many a case of infectious disease, with all its dangers to life or to important organs, such as the thyroid, may be avoided by proper circumspection.