240 THE OEIGIN AND PEOPAGATION OF DISEASE. 



the possibility of spontaneous generation within limited and exceptional 

 conditions, there is hardly a doubt remaining that as a rule, in the 

 regular operations of nature, the Bacteria or their germs are, in point of 

 fact, conveyed from one i)utrefying substance to another, and that putre- 

 faction is a process excited by contagion, and accomplished only by the 

 growth and nutrition of Bacteria. 



It was an important discovery, when it was found, ten years ago, that 

 Bacteria might be developed in the interior of the living animal or- 

 ganism. In 1863 an d 1864, Davaine* showed that in the disease of sheep, 

 khown in France as " cliarhon " or " sang de rate,''' and called by the 

 Germans " milzbrand,''^ the blood of the aifected animal, during life, con- 

 tained Bacterid. He showed that the disease might be communicated by 

 inoculation to other animals, always with a fatal result, and always with 

 the development of Bacteria in the blood previous to death. He after-, 

 wardt extended the same observation to cases of malignant pustule, 

 which he declared to be one form of the ^'■saiig de rate " disease. 



In 1868 Vulpiauf found that a fatal disorder might be produced in 

 frogs hj the administration of cyclamine ; that the malady was accom- 

 panied by the development of Bacteriam the blood, and that inoculation 

 of this blood reproduced the disease in other healthy animals of the same 

 species. 



About the same time, Professors Coze and Feltz,§ formerly of the 

 University of Strasbourg, had been making researches in a similar direc- 

 tion. They ejected putrescent liquids into the veins or subcutaneous 

 tissue in dogs and rabbits, producing in this way a fatal artificial sep- 

 ticmmia; and they found that Bacteria were developed in the blood of 

 the animal simultaneously with the appearance of the febrile' condition. 

 But the effect produced did not stop there. The blood of such an animal, 

 though not itself putrid, had become uifectious, and would excite septi- 

 cwmia in another animal by inoculation. A still further remarkable re- 

 sult was obtained from these experiments : " By rei^roducing in this 

 manner," the authors say, " several successive inoculations, it becomes 

 evident that the infectious element is at last more active than the putres- 

 cent matters themselves. Injection of putrescent liquids is not so rapidly 

 fatal as inoculation of the blood of an animal ah-eady infected." 



These facts have been confirmed by the observations of Davaine and 

 Yulpian, which show the extraordinary activity of infectious blood, even 

 at a high degree of dilution. Davaine|| found that putrefied bullock's 

 blood, injected into the subcutaneous tissue of the rabbit, was rarely 

 fatal in doses of less than yi^ of a drop, and never so in less than ■go'oov 

 But a series of twenty-five successive inoculations showed that septi- 

 caemia, once established, could be transnaitted to the healthy rabbit by a 



* "Comptes Eendus de l'Acacl6mie des Sciences," tomes Ivi, lis. 



t " Comptes Eendus," 1865, tome Ix, p. 1297. . 



t " ArcMves de physiologic normal e et patliologique," 1868, p. 466. 



§ " Eecherches cliniques et experimentales sur les maladies infectieuses," Paris, 1872. 



II " Bulletin de I'Acaddmie de M6decine," Septembre 17, 1872. 



