94 



Scientific Proceedings (73). 



Saequepee and Loiseleur on the other hand found resistance 

 lowered by high heating, but for the most part their experiments 

 were concerned with the lighting up of latent infection or the 

 invasion of bacteria from the digestive tract, a very different 

 phenomenon from the progress of the struggle for immunity against 

 an infection already established. 



Finally there is another type of experiments in which the 

 effects upon vital resistance of a moderately high temperature 

 (3° 0_ 35°) have been studied; and these experiments yield results 

 quite different from those which have just been reviewed. While 

 a temperature approaching 40 0 by producing a state of fever 

 appears to favor recovery from an infectious disease, a somewhat 

 lower temperature seems to exert a lowering effect on general vital 

 resistance without the compensating stimulation of vital processes 

 which may accompany the development of fever. Five different 

 investigations, the only ones with which we are familiar bearing 

 on this point, all warrant the same conclusion. Fermi and 

 Salsano (1892) found that a strain of avian tubercle bacilli which 

 was incapable of producing a general infection in normal guinea 

 pigs could be found in abundance in the glands of animals kept 

 at 33°-35°. Similarly mice when heated showed many more 

 tubercle bacilli, of both avian and human types, in their glands 

 than did control animals; and the infection was still further 

 increased by combining high humidity with the high temperature. 

 Graziani (1906) studied the agglutinating power of the blood of 

 rabbits kept at various temperatures. At 2° to 4 0 the blood would 

 agglutinate at a dilution of I in 1541 ; at 18 0 , I in 854; at 32 0 , 

 I in 727. In another series the blood of rabbits kept at 32 0 

 agglutinated at a dilution of 1 in 1250 while if the animals were 

 occasionally relieved by cold baths the agglutinating power rose 

 to I in 2425. Ritzmann (1907) kept guinea pigs, white rats and 

 mice at 35 0 and found that heated animals died from half a day 

 to three and a half days after injections of streptococci, control 

 animals after one and a half to eight days. Injections of toxin- 

 free tetanus spores and of tetanus spores plus streptococci yielded 

 similar results. Ritzmann also cites experiments of Wysso- 

 kowitsch leading to the same conclusion. Finally Ruata (1909) 

 kept guinea pigs at a temperature of 30 0 with a relative humidity 



