Tlie President's Address. By Rev. W. H. Bollinger. 179 



in an optically pure or absolutely calcined air ; while these con- 

 ditions are maintained, no matter what length of time may be suffered 

 to elapse, the putrescible fluid will remain absolutely without trace of 

 decay ; but suffer the slightest infection of the protected and pure 

 air to take place, or, from some putrescent source, inoculate your 

 sterilized fluid with the minutest atom, and shortly turbidity, offen- 

 sive scent, and destructive putrescence ensue. 



As in the alcoholic, lactic, or butyric ferments, the process set up 

 is shown to 1 e dependent upon and concurrent with the vegetative 

 processes of the demonstrated organisms characterizing these fer- 

 ments, so it can be shown with equal clearness and certainty that 

 the entire process of what is known as putrescence is equally and 

 as absolutely dependent on the vital processes of a given and dis- 

 coverable series of organisms. 



Now it is quite customary to treat the fermentative agency in 

 putrefaction as if it were wholly bacterial ; and indeed the putrefac- 

 tive group of bacteria are now known as saprophytes, or saprophytic 

 bacteria, as distinct from morphologically similar, but physiologically 

 dissimilar forms known as parasitic or pathogenic bacteria. 



It is indeed usually, and justly admitted, that B. termo is the 

 exciting cause of fermentative putrefaction. Cohn has, in fact, con- 

 tended that this is the distinctive ferment of all putrefactions, and 

 that it is to decomposing proteinaceous solutions what Torula cerevisim 

 is to the fermenting fluids containing sugar. 



In a sense this is no doubt strictly true. It is impossible to find 

 a decomposing proteinaceous solution at any stage without finding this 

 form in vast abundance. 



But it is well to remember that in nature putrefactive ferments 

 must go on to an extent rarely imitated or followed in the laboratory. 

 As a rule the pabulum in which the saprophytic organisms are pro- 

 vided and " cultured " is infusions, or extracts of meat carefully 

 filtered ; and if vegetable matter is used, extracts of fruit, treated 

 with equal care, and if needful neutralized, are used in a similar way. 

 To these may be added all the forms of gelatin, employed in films, 

 masses, and so forth. 



But in following the process of destructive fermentation, as it 

 takes place in large masses of tissue, animal or vegetable, but far 

 preferably the former, as they lie in water at a constant temperature 

 of from (i0° to 65° F., it will be seen that the fermentative process 

 is the work, not of one organism, nor, judging by the standard of 

 our present knowledge, of one specified class of vegetative forms, but 

 by organisms which, though related to each other, are in many 

 respects greatly dissimilar, not only morphologically, but also ernbryo- 

 logically and even physiologically. 



Moreover, although this is a matter that will want most thorough 

 and efficient inquiry and research to understand properly its condi- 

 tions, yet it is sufficiently manifest that these organisms succeed each 

 other in a curious and even remarkable manner. Each does a part 



