130 THE GERM THEORY OF DISEASE. 



teristic and constant, and are in no case preceded by any of 

 the symptoms of poisoning previously described." 



These experiments show very distinctly that the experi- 

 menter was dealing with a diffusible poison of virulent 

 character, produced by the organisms, but acting without 

 them, as the alkaloids from the higher plants would act. 



Dr. Sternberg says (page 257): " It is not alone by invad- 

 ing the blood or tissues that bacteria exhibit pathogenic 

 powers. Chemical products evolved during their vital activ- 

 ity, external to the body, or in abscesses and in suppurating 

 wounds, or in the alimentary canal, may doubtless be absorbed, 

 and exercise an injurious effect upon the animal economy. 

 Indeed, we have experimental evidence that most potent 

 poisons are produced during the putrefactive decomposition of 

 organic matter. The poisons resembling the vegetable alka- 

 loids in their reactions^ called ptomains by Selmi, who first 

 obtained them from the cadaver, are fatal to animals in 

 extremely minute doses." 



Klebs said, at the International Medical Congress at 

 London, that the effects of micro-organisms were probably 

 due to fine chemical workings. Very many of the experi- 

 menters in this field have spoken in a, like manner of their 

 findings, all of which go to show that the worker in this line 

 of research soon comes to feel that he is dealing with a poison 

 evolved by the organisms he has under observation. 



Gradle says (page 66): "The successive chemical stages of 

 the putrefactive change have as yet been incompletely traced. 

 The changes which albumen undergoes resemble at first the 

 process of digestion. It is converted into soluble forms, 

 partly peptone, and then split up into leucin and tyrosin. Sub- 

 sequently numerous volatile fatty acids, and various poly- 

 atomic alcohols (phenol, skatol, indol), appear, as well as a 

 host of other substances in traces. Amongst them are a variety 



