TYPHOID FEVER IlST DISTRICT OF COLUMBIA. 
91 
which the Rye Beach epidemic, carefully studied by Nichols,® of 
Boston, in 1875, is a point in evidence, the case is different with 
typhoid fever. In only a few isolated instances has ice been accused 
of being the vehicle by which the infection of typhoid fever has been 
spread. 
Sedgwick and Winslow^ (1902), after reviewing the literature upon 
the subject of ice supply and public health, express the opinion that 
no epidemic of typhoid fever has been satisfactorily traced to such a 
source. They point out the fact that, while it is known that cultures 
of typhoid fever are not sterilized by freezing, the important question 
of the quantitative reduction of this species by freezing had been stud- 
ied in only two limited investigations. They therefore froze large 
numbers of tubes inoculated with four different races of the typhoid 
bacillus and determined the reduction after various periods. 
Sedgwick and Winslow draw the following poignant deductions: 
‘‘ Reviewing the several series of experiments described in detail, and 
keeping carefully in mind the conditions under which natural ice is 
formed, cut, harvested, stored, delivered, and finally consumed, as 
well as those pertaining to the manufacture, distribution, and con- 
sumption of artificial ice, certain conclusions appear to be justified 
concerning ice as a vehicle of disease, and these conclusions are, on 
the whole, decidedly reassuring. 
‘‘ The conditions which tend naturally to purify polluted waters are 
now well understood. Light, cold, and pure-food supply are anti- 
septic or disinfectant agents of considerable power; hostile infusoria 
may devour the living germs of infectious disease ; the chemical com- 
position of the water may be unfavorable to their survival, and grav- 
ity may cause them to settle to the bottom, where they may soon 
perish for want of air. The main factor determining the reduction 
of germs in water is, however, the time — the time during which these 
and other forces are left to act. Epidemiology shows clearly that 
disease follows best a direct quick transfer of infectious material 
from patient to susceptible victim, and, if storage of water for some 
months could be insured, many sanitarians would consider such stor- 
age a sufficient purification. 
‘ ‘ In ice we have this condition realized — a forced storage of at least 
“ Nichols, A. H. : Report on an outbreak of intestinal disorder attributable to the 
contamination of drinking water by means of impure ice. Seventh Ann. Rep. , S. B . H. , 
Mass., 1876, p. 467. 
& Sedgwick, W. T., and Winslow, C.-E. A.: Experiments on the effect of freezing 
and other low temperatures upon the viability of the bacillus of typhoid fever, with 
considerations regarding ice as a vehicle of infectious disease. 2. Statistical studies 
on the seasonal prevalence of typhoid fever in various countries and its relation to 
seasonal temperature. Mem. Am. Acad. Arts & Sci., vol. 12, no. 5, Aug., 1902. Sum- 
mary, Boston Soc. Med. Sci., 1899-1900, v. 4, p. 181. 
