is good reason to believe that the bacillus of bubonic plague may be transmitted in the same way. The cholera spirillum is quickly killed by desiccation and this disease is probably very rarely, if ever, communicated through the medium of dust. But the germs of typhoid fever and of bubonic plague are more resistant and, without doubt, under certain circumstances, these diseases are extensively propagated by means of dust containing desiccated excreta. There is a good reason to believe that in several of our camps, during the Spanish-American War, this was an important factor in the etiology of typhoid fever epidemics. The average mortality from typhoid fever in our regular army since the Civil War has been, for the first decade (1868-1877) 95 per 100,000 of mean strength; for the second decade (1878-1887) 108 per 100,000, for the third decade (1888-97) 55 per 100,000. This latter rate compares favorably with that of many of our principal cities; for example, it is exceeded by the typhoid death-rate of the city of Washington, which is 78.1 per 100,000 (average of 10 years, 18881897), by that of the city of Chicago, which is 64.4 per 100,000; by that of Pittsburgh, which is 88 per 100,000. As a result of insanitary conditions existing in the camps in which our troops were hastily assembled at the outset of the Spanish-American War, the typhoid death-rate in our army of volunteers and regulars during the year ending April 30, 1899, was more than 22 times as great as it had been in our regular army during the decade immediately preceding the war period. As compared with the Civil War, however, there was a decided improvement, the typhoid mortality for the first year of the Civil War having been 1,971 per 100,000 of mean strength and for the Spanish-American War 1,237 per 100,000.
Experience shows that new levies of troops are especially subject to typhoid fever and other infectious 'camp diseases,' not only because of lack of discipline and consequent difficulty in the enforcement of sanitary regulations, but also because the individual soldiers are very susceptible to infection, owing to their age, the abrupt change in their mode of life, the exposure and fatigue incident to camp life, and last, but not least, their own imprudence as regards eating, drinking, exercise, etc. In the absence of sewers or other adequate means of removing excreta, the camp site is likely to become infected by the discharges of unrecognized cases of typhoid and typhoid bacilli are carried by flies to the kitchens and mess-tents and deposited upon food, or as dust are directly deposited upon the mucous membranes of the respiratory passages of those living in the infected camp. That preventive medicine has still serious work before it is shown by the fact that according to the last census return there were 35,379 deaths from typhoid fever in the United States during the census year 1900. The increase in mortality over the number in 1890 (27,056) is out of proportion to the
