CHAPTER III. 



A HISTORICAL SKETCH OF THE BACTERIAL POISONS. 



The history of man's experiments with, and his investigations of, 

 the bacterial poisons quite naturally divides itself into three periods. 

 During the first period man was ignorant of the existence of bacteria 

 and of the r6le that they play in processes of putrefaction, as well 

 as in the causation of disease, and in his experiments he did not al- 

 ways adopt measures which are necessary for the destruction of liv- 

 ing microorganisms ; consequently the results obtained were in some 

 instances due wholly to infection, in others to bacterial chemical 

 poisons, while in still others both the toxin and the bacterium prob- 

 ably had some influence in causing the phenomena which he ob- 

 served. In the second period man recognized the existence of bac- 

 teria and made his experiments with sterilized products. But he 

 had not at that time secured the information necessary to enable him 

 to isolate and classify the microorganisms ; therefore, the toxins with 

 which he worked resulted, as a rule, at least, from the growth of 

 mixed cultures of germs, the characteristics of which he did not 

 know. Indeed, most of the experiments of the time were made 

 with sterilized substances obtained from putrefying material. The 

 third period was reached when the experimenter worked with pure 

 cultures and for the first time was able to proceed scientifically in 

 his investigations. 



It must have been known to primitive man that the eating of 

 putrid flesh was liable to be followed by more or less harmful effects, 

 and when he began his endeavors to preserve his food for future 

 use, instances of poisoning from putrefaction must have multiplied. 

 However, the distinguished physiologist, Albert von Haller, seems 

 to have been the first to make any scientific experiments concerning 

 the action of putrid material upon animals. He injected aqueous 

 extracts of decomposing flesh into the veins of various animals and 

 found that death frequently resulted. Later in the eighteenth century, 

 Morand gave an account of the symptoms induced in man by eating 

 putrid meat. In the early part of the nineteenth century (1808-1814) 

 Gaspard carried on similar experiments. His studies were made 

 with the putrefied flesh of both carnivorous and herbivorous animals. 

 With these he induced marked nervous disturbances, as stiffness of 

 the limbs, opisthotonos and tetanus, and he concluded from the 

 symptoms thus induced that the poisonous effects were not due to 

 carbonic acid gas or hydrogen sulphid, but thought it possible that 



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