Of all diseases which have wrought devastation to the human race, there has never been a disease more deadly or more widely distributed than tuberculosis. Other communicable diseases have caused more dismay, and occasionally, for a short period, even greater destruction; but tuberculosis has been, and to a lesser degree continues to be, the most constant and virulent of all. It has been recently estimated that there are one million cases of active tuberculosis in the United States, and the latest authentic statistics show that 14 per cent. of the deaths recorded for ten years are due to some form of it.
Climate, as affected by mere latitude, does not seem to have any influence on the disease. The death-rate from this cause is practically the same in New York, at a latitude of 44 degrees, and Manila, which is only 15 degrees from the equator. On the other hand,