CONDITIONS FATOimiNG FERMENTATION. 65 



chemical actions. The most familiar of such bodies are ptyalin, 

 pepsin, pancreatin, of animal origin, with diastase, emulsin, and 

 myrosin, as products of certain vegetable tissues. And when we 

 learn that the actions brought about by these bodies are also 

 nearly all of them capable of being induced by mere acids and 

 alkalies acting under known conditions, much of that air of mys- 

 tery seems stript from fermentative processes which Pasteur's 

 definitions are calculated to inspire*. 



The products of the animal and the vegetal organism are many 

 of them capable of being built up by synthetic processes in our 

 laboratories. No one now will venture to say that though such 

 or such bodies can be artificially engendered, certain other organic 

 compounds cannot, and never will be, so produced ; and the same 

 may be said in regard to actions supposed only to be producible 

 by the direct agency of living units. As M, Schutzenberger says, 

 in the preface to his work on ' Fermentation ' : — " If living cells 

 produce reactions which seem peculiar to themselves, it is because 

 they realize conditions of molecular mechanism which we have 

 not hitherto succeeded in tracing, but which we shall, without 

 doubt, be able to discover at some future time. Science can gain 

 nothing by being limited in the possibility of the aims which she 

 proposes to herself, or the end which she seeks." 



But we must now turn to another side of the question, and see 

 how, with increasing knowledge and new surmises concerning the 

 death-point and life-history of ferment-organisms, possibilities of 

 a new order in regard to their survival under adverse circum- 

 stances have been opened up. We must try also to estimate their 

 relative worth. 



In the year 1871t I made the first recorded experiments to 

 ascertain at what precise temperature below 212° F., Bacteria, 

 Torulae, and their germs were killed. These experiments were 

 conducted by adding a drop or two of a fluid swarming with such 

 organisms to an artificially prepared nourishing solution (having 

 a neutral reaction), in which they had been found to multiply 

 rapidly, and then after exposing this inoculated mixture to defi- 

 nite temperatures for a certain time, putting it aside under favour- 

 able conditions to see whether it would or would not become 



* Schutzenberger, ' On Fermentation ' (English translation), in International 

 Scientific Series, 1876, pp. 269-307. 



t ' Modes of Origin of Lowest Organisms,' 1871, p. 50. 

 LINN. JOUEN. — ZOOLOGY, VOL. XIV. 6 



