IMMUNITY AND SUSCEPTIBILITY. 109 



large measure destroyed by feeding the animals upon 

 bread. 



The natural diet may have something to do with sus- 

 ceptibility, for in anthrax we find that the herbivorous 

 animals are all rather easily infected, while the carnivor- 

 ous animals are infected with difficulty. 



f. Effect of Drugs, etc. — In the experiments of Platania, 

 immune animals, such as frogs, pigeons, and dogs, were 

 found to become susceptible to anthrax when under the 

 influence of curare, chloral, or alcohol. Leo found that 

 when white rats were fed upon phloridzin a glycosuria 

 developed, during which they become susceptible to 

 anthrax. 



Wagner 1 found that pigeons become susceptible to 

 anthrax when under the influence of chloral. 



It is a common observation that alcoholics are predis- 

 posed to croupous pneumonia. The experimental demon- 

 stration of the effect of alcohol in increasing susceptibility 

 to disease is, however, difficult. Abbott's 2 comprehen- 

 sive work in which a large number of rabbits were daily 

 intoxicated with alcohol (5-15 c.c.) introduced into the 

 stomach through a rubber catheter, showed that the 

 vital resistance to infection by the streptococcus pyogenes 

 and bacillus coli communis was diminished. 



g. Operative manipulations may destroy immunity. 

 The value of the spleen in preventing infectious diseases 

 has been studied by a number of observers, but their 

 results are conflicting. Thus, Bardach, 3 Righi, 4 and 

 Montuori 5 found that the removal of the spleen increased 

 susceptibility to infection ; Blumenreich and Jacoby 6 

 found that its removal was followed by a hyperleukocyto- 

 sis, increase in the germicidal power of the blood, and 

 corresponding increase in immunity; while Milkinow- 



1 Wratsch, 1890, 39, 40. 



1 Journal of Experimental Medicine, vol. i., No. 3, 1896. 



* Ann. de P Inst. Pasteur, 1889, No. 2, p. 577 ; 1891, No. I, p. 40. 



4 La Riforma Medica, 1 893, pp. 170, 1 7 1. 



s Ibid., Feb., 1893, 17, 18. 



« Berliner klin. Wochenschrift, May 24, 1897. 



