As in rabies, the parasite, if it is a parasite, acts through a poison which penetrates to the nervous centers, producing mental disturbances culminating in an active insanity. At the same time, the agent attacks the skin, whence its name "pell'agra," which means "rough skin," so that the body appears as if it were affected with a severe attack of eczema, large patches of skin peeling off and leaving the raw surface. In fact, in one of the Illinois hospitals, only a few years ago, some insane persons, infected with this disease, died, and because the effect of the disease on the skin was not known, the nurse in charge was accused of scalding the patients with boiling water, the appearance of the skin being the only proof. The nurse was discharged, although, without doubt, she was innocent, and the appearance of the skin was due solely to the disease. It has been estimated that there are at present in the United States five thousand victims of pellagra, with the number constantly increasing, although physicians of standing make estimates largely in excess of this. Apparently preventive measures must consist in eliminating the possibility of the use of spoiled corn. Indications are that the disease appears only when such corn has been used, and in parts of Mexico where corn is always roasted before being used, pellagra is never known. It has been described as a disease of the poor, because the disease has flourished chiefly in districts where poverty is so extreme that corn, and spoiled corn at that, is the only food within reach. Usually, where a mixed diet with meat is possible, pellagra never appears. In other places, as in Italy, where the peasants live on a porridge of corn meal cooked in great potfuls, a week's supply at a time, and during the week exposed to dirt and flies and often spoiled before eating, pellagra is most common. Experiments have shown that in these districts, by excluding corn from the diet and furnishing a substantial fare, the disease has been banished. Unfortunately, the taint of the disease passes from parent to child and even to the third and fourth generation, and the physical deformities commonly seen in pellagrous districts are due to this hereditary taint. Dr. Babcock, Superintendent of the City Hospital at Columbia, South Carolina, after discussing the disease, sums up by saying, "Pellagra is a fact, and the United States is facing one of the great sanitary problems of modern times." _Bubonic plague._ The bubonic plague, or "The plague," as the importance of the disease has caused it to be called, is one of the oldest of known epidemics. In the third century it spread through the Roman Empire, destroying in many portions of the country nearly one-half of the people. Its immediate origin is a bacillus causing symptoms similar to blood poisoning, although in some cases, where the lungs are attacked, the disease has some of the characteristics of pneumonia.