154 BACTERIAL POISON'S. 



various species of animals (rabbits, mice, pigeons, and 

 slieep) and found tliat this blood destroyed the bacillus 

 anthracis, bacillus subtilis, bacillus megateriura, and staphy- 

 lococcus pyogenes aureus when brought in contact with 

 them. NisSEN continued this work and employed blood- 

 serum as well as defibrinated blood. The conclusions 

 reached were as follows : 



(1) The addition of small quantities of sterilized salt- 

 solution or bouillon to the blood does not destroy its 

 germicidal properties. 



(2) Cholera germs and Ebeeth's bacilli are easily de- 

 stroyed by fresh blood 



(3) For a given volume of blood thei'e is a maximum 

 amount of bacilli which can be added. If too many 

 germs are used the destruction is incomplete. 



(4) Blood whose coagulability has been destroyed by 

 the injection of peptone is still germicidal. 



(5) Filtered blood-plasma from the horse is germicidal. 

 Beheing has attributed the action of the blood of 



white rats on anthrax bacilli to the presence of a hypo- 

 thetical basic body to which the decidedly alkaline reaction 

 of the blood is supposed l)y him to be due. Later, he lays 

 special stress upon the amount of carbonic acid gas in the 

 blood-serum. 



Bdchnee has made a most exhaustive study of this 

 subject, in which he has been aided by VoiT, Sittmann, 

 and Oethenbergee. The results of this work are stated 

 as follows : 



(1) The germicidal action of the blood is not due to 

 phagocytes, because it is not influenced by freezing and 

 thawing the blood, by which the leucocytes of the blood 

 of the rabbit are destroyed. 



(2) The germicidal properties of the cell-free serum must 

 be due to soluble constituents. 



(3) Neither neutralization of the serum, nor the addition 

 of pepsin, nor the removal of carbonic acid, nor treatment 

 with oxygen have any effect upon the germicidal proper- 

 ties of the blood. 



(4) Dialysis of the serum against water destroys its 



