GERMICIDAL ACTION 247 



In 1890, Buchner with Voit, Sittmann, and Orthen- 

 berger came to the conclusion that the germicidal action 

 of cell-free serum is due to the protein constituents, and 

 a germicidal protein was obtained from the spleen by 

 Christmas and Bitter. 



Behring and Nissen, however, found that while the 

 serum of the white rat, dog and rabbit destroys the 

 Bacillus anthracis, serum from the mouse, sheep, guinea- 

 pig, chicken, pigeon, and frog has no action. Thus, while 

 the rabbit is highly susceptible to anthrax, its serum is 

 germicidal ; the chicken, on the other hand, is immune to 

 anthrax, but its serum is inactive. Hence there is no 

 necessary correspondence between the action of circulating 

 blood and that of extra-vascular blood. 



Vaughan, Novy, and McClintock ascribed powerful 

 bactericidal properties to the nucleins, and surmised that 

 in serum the nucleins set free by the disintegration of 

 leucocytes and other cells are the germicidal agents. 

 Forrest and the author 1 found, however, that all the 

 germicidal properties ascribed by Vaughan to the nucleins 

 were probably due to the weak alkali used. 



Gengou also found that the plasma collected in vaselined 

 tubes is often almost devoid of bactericidal power, whilst 

 the corresponding serum may be capable of destroying 

 large numbers of micro-organisms. 



We therefore see that while blood, lymph, and tissue 

 juices frequently exert more or less germicidal action on 

 bacteria experimentally in vitro, the intact and circulating 

 blood may be quite devoid of this action, and it may be 

 doubted, therefore, if this factor of germicidal power is 

 of much importance in the production of natural immu- 

 nity. At the same time, it is to be noted that directly 

 infection has started more or less cellular disintegration 



1 Journ. Roy. Army Med, Corps, 1904. 



