24 Introduction 



crude methods at his disposal. They were so ably elabo- 

 rated, however, that in after years they were again postulated 

 by Koch, and it is only by strict conformity with them 

 that the definite relationship between bacteria and disease 

 has been determined. 



Briefly summarized, these requirements are as follows: 



1. A specific micro-organism must be constantly asso- 

 ciated with the disease. 



2. It must be isolated and studied apart from the disease. 



3. When introduced into healthy animals it must pro- 

 duce the disease, and in the animal in which the disease 

 has been experimentally produced the organism must be 

 found under the original conditions. 



In 1843 Dr. Oliver Wendell Holmes wrote a paper upon 

 the l< Contagiousness of Puerperal Fever." 



In 1847 Semmelweiss, of Vienna, struck by the similarity 

 between fatal wound infection with pyemia and puerperal 

 fever, cast aside the popular theory that the latter affection 

 was caused by the absorption into the blood of milk from 

 the breasts, and announced his belief that the disease 

 depended upon poisons carried by the fingers of physicians 

 and students from the dissecting room to the woman in 

 child-bed, and recommended washing the hands of the 

 accoucheur with chlorin or chlorid of lime, in addition to 

 the use of soap and water. He was laughed to scorn for 

 his pains. 



In 1849 J. K. Mitchell, in a brief work upon the "Crypto- 

 gamous Origin of Malarious and Epidemic Fevers," fore- 

 shadowed the germ theory of disease by collecting a large 

 amount of evidence to show that malarial fevers were due 

 to infection by fungi. 



Pollender (1849) and Davaine (1850) succeeded in 

 demonstrating the presence of the anthrax bacillus in 

 the blood of animals suffering from and dead of that dis- 

 ease. Several years later (1863) Davaine, having made 

 numerous inoculation experiments, demonstrated that this 

 bacillus was the materies morbi of the disease. The bacillus 

 of anthrax was probably the first bacterium shown to be 

 specific for a disease. Being a very large bacillus and a 

 strongly vegetative organism, its growth was easily observed, 

 while the disease was one readily communicated to animals. 



Klebs, who was one of the pioneers of the germ theory, 

 published, in 1872, a work upon septicemia and pyemia, 



