132 TEXT-BOOK OF BACTERIOLOGY. 



state are impervious to bacteria. In the urine, for example, micro- 

 organisms are only to be found when a way has been opened to them 

 by some injury to the urinary passages, some rupture of a vessel. 



Wyssokowitsch found that the micro-organisms are deposited 

 at their chief points of development by the blood-currents, namely, 

 in the spleen, the liver, and the spinal marrow, and he believed that 

 here they either perished or multiplied showed themselves non- 

 pathogenic or pathogenic. 



That in reality a destruction of bacteria does take place in the 

 bodies of living animals was proved by Fodor. Petruschky discov- 

 ered that the blood of animals insusceptible to anthrax, such as 

 frogs, killed anthrax bacilli even when all cellular portions \vere 

 carefully excluded, Behring showed that the serum of white rats, 

 even when separated from the bod3 r , possessed this capability. 

 Nuttall was able to prove the same with regard to the aqueous 

 humor, the ascites fluid, and other juices of the body, and this 

 bacteria-destroying power of the blood-serum has obtained a more 

 universal importance from the independent, though simultaneous, 

 labors of H. Buchner and Nissen. The results of their investiga- 

 tions may be summarized in a few words, as follows: Germ-free 

 serum kept for several days at a low temperature has the power 

 of killing bacteria-germs in a very short time. It is true that this 

 capacity has its limits. If one inoculates more than a certain 

 quantity of micro-organisms some will be killed, but for the sur- 

 vivors the serum, instead of remaining a hostile element, becomes 

 a source of aliment, and the bacteria begin to increase in it. 



The different species show considerable differences of behavior 

 in this respect. While some are particularly sensitive and sure to 

 perish if brought into contact with serum, others are not in the 

 least affected by it; and between these two groups is another, in 

 which at first a slight check to development is observed, but which 

 the bacteria soon get over and then proceed to grow and increase. 



The germ-killing, disinfecting power lies exclusively in the 

 plasma; the cellular parts of the blood, the red and white corpus- 

 cles even, counteract and paralyze it. Under the influence of high 

 temperatures it quickly disappears, as already noted; it is also 

 diminished by the blood being left standing for a length of ti-me, 

 but repeated freezings and thawings do not affect it. 



Both investigators see a connection between this peculiar prop- 

 erty of the serum and the processes which contribute principally 

 to the coagulation of blood. This, however, does not tell us much 

 about the exact nature of the active principle, but a subsequent 

 series of investigations by Buchner found that the germ-killing 



