118 Transactions of the Society. 



organisms (contagia animata), but describes them (as if in terms of 

 physical chemistry) as something very like our modern ' colloidal 

 systems,' although he regards them as capable of reproduction in 

 appropriate media. As between Fracastorius and Athanasius 

 Kircher, the decision of priority in regard to the germ theory will 

 depend upon whether the arbiter is a materialist or a vitalist." * 



When Kircher, Swammerdam, Hooke, Leeuwenhoek demon- 

 strated the presence of minute organisms in decomposing matter, 

 in material taken from carious teeth and in the excreta of patients 

 suffering from diarrhoea, they laid the foundation of our present 

 knowledge of specific infective diseases, and, imperfect as that 

 knowledge is, it has enabled those working at the cure and pre- 

 vention of disease to initiate and carry out a plan of campaign 

 that has reduced mortality aDd diminished suffering to an extent 

 that could not have been anticipated even later than half a century 

 ago. At the time they were obtained the findings of these 

 observers were accepted as curious and interesting, no doubt, but 

 as being of so little practical importance that few workers deemed 

 it necessary to continue them or to make any special deductions 

 from them. Later, however, Donne, finding vibrios in pus as well 

 as in the secretions and excretions of the human subject, made a 

 real attempt to connect the presence of microscopic organisms 

 with the occurrence of an infective disease. In all probability 

 Donne's observations were incorrect, or rather his deductions 

 therefrom, for in 1837 he appears to have convinced himself that 

 the presence of these organisms was purely accidental. His 

 observations, however, suggested a new meaning and importance 

 for the study of vibrios and monad-like organisms, and micros- 

 copists of all degrees of eminence took up their study, and there 

 followed a time of preparation for the great advance that was 

 made forty or fifty years later by Pasteur, Koch, and Lister. 

 There had, of course, been preliminary tilling of the ground, but in 

 1837 Theodor Schwann,! a German anatomist and physiologist, 

 and Cagniard Latour,| a French chemist, working independently, 

 demonstrated that Leeuwenhoek's yeast globules present in fer- 

 menting beer and wine were really living organisms, probably 

 plants, of a low order, which, multiplying by budding and by 

 fission, might be regarded as setting up fermentation by their 

 vital activities. With this observation in their minds, and study- 

 ing the course of certain infective processes, they came to the 

 conclusion that both fermentation and disease might be the result 

 of the vital activity of similar, if not identical, organisms. Bohm, 

 with his Microscope, looked for and found yeasts in the intestinal 



* An Introduction to the History of Medicine, by Fielding H. Garrison, 

 A.B., M.D., 1913. 



t Mittb. a. d. Verbandl d. Gesellscb. Naturf., Berlin, Bd. ii. s. 9. 

 X Ann. d. Cbim. et Pbys., Paris, 1838, t. lxviii. p. 206. 



