102 BACTERIAL POISONS. 



fects might be found hack of the eye and in the brain. But 

 in 1863, DAVAINE showed that these little bodies must 

 have some causal relation to the disease, inasmuch as his 

 experiments proved that inoculation of healthy animals 

 with the blood of those sick with anthrax produced the 

 disease only when taken at a time when the blood con- 

 tained these organisms. He also demonstrated beyond any 

 question that these rod-like bodies are bacteria, capable of 

 growth 'and multiplication. The conclusions of this investi- 

 gator were combated by many ; but PASTEUR, KOCH, 

 BOLLINGER, DE BARRY, and others, studied the morph- 

 ology and life-history of these organisms, and then came 

 the brilliant results of PASTEUR and KOCH in securing 

 protection against inoculation anthrax by the vaccination 

 of healthy animals with the modified germ and subsequent 

 inoculation with the virulent form. Now, the bacillus 

 anthracis is known in every bacteriological laboratory, and 

 by inoculation with it the disease is communicated at will 

 to susceptible animals. But here the question arose, How 

 do these bacilli produce anthrax? and in answer to this 

 question the various theories which we have mentioned 

 were proposed. 



The first successful attempt to study the chemical poisons 

 of anthrax was made by HOFFA, who obtained from pure 

 cultures of the bacillus small quantities of a ptomaine, 

 which, when injected under the skin of animals, products 

 the symptoms of the disease and death. This substance 

 causes at first increased respiration and action of the heart, 

 then the respirations become deep, slow, and irregular ; 

 the temperature falls below the normal; the pupils are 

 dilated, and a bloody diarrhoea sets in. On section the 

 heart is found contracted, the blood dark, and ecchymoses 

 are observed on the pericardium and peritoneum. HOFFA 

 names his poison anthracin. Recently HOFFA has isolated 

 this poison from the bodies of animals dead from anthrax. 



It has been said that HOFFA 's work was the first suc- 

 wssful attempt to study the chemical poisons of anthrax. 

 However, his results cannot l>e considered altogether satis- 

 factory. The small amount of the basic substance which 



