MICROPHYTES FOUND IN THE BLOOD. 363 



yeast, . . . The fermentation alluded to is regarded as a 

 particular instance of a biological reaction, manifesting itself as 

 the result of a special force residing in organisms ; or, in other 

 words, fermentation is essentially a correlative phenomenon of a 

 vital act, beginning and ending with it. On this hypothesis, 

 where there is fermentation there is organisation, development, 

 and multiplication of the globules of the ferment itself. The 

 instance quoted above is by no means solitary ; it is exemplary 

 of many other changes, induced by the same or other fermented 

 matters in media suitable for their growth and reproduction. 

 Thus, we have mannitic, lactic, ammoniacal, and butyric 

 fermentations, besides many others, all of them having one 

 feature in common, viz. the reproduction of the ferment.^ It 

 has not yet, however, been satisfactorily ascertained — a very essen- 

 tial matter to be settled before the foregoing interpretation of 

 fermentative processes can be established — that the several 

 processes are the result of the action of specifically distinct 

 growths. 



Baron Liebig vigorously opposed this doctrine, and Mr. 

 Kingzett suggests, probably ignored the influence, of vital action 

 to too great an extent ; all that was required in his opinion for 

 inducing the fermentative change was contact with matter which 

 was itself undergoing change. Mr. Kingzett thus sums up the 

 physico-chemical doctrine of fermentation as advanced by 

 Liebig : — Mechanical or other motion exerts an influence on 

 the power which determines the state of a body. Thus, a 

 crystal of sulphate of sodium, a speck of dust, or grain of 

 sand, when dropped into a saturated solution, say of sulphate of 

 sodium, may determine the entire crystallisation of the fluid. 

 Or, again, when fulminates of silver and mercury are tickled 

 lightly by a feather or glass rod, they suddenly explode with 

 violence. A still better instance is the reaction which occurs 

 between peroxide of hydrogen and argentic oxide ; these sub- 

 stances, when mixed, give rise to the production of metallic 

 silver and free oxygen ; the peroxide of hydrogen, being un- 

 stable, is constantly undergoing decomposition from the moment 

 of its formation, and this decomposition results in the pro- 

 duction of water and free oxygen ; immediately, therefore, that 

 this change comes into contact with oxide of silver, it gives to 

 that body the same tendency to change. 



A. — The Organisms found in the Blood in Splenic Fever. 



On the assumption that certain diseases which are undoubtedly 

 communicable by inoculation, and several others commonly be- 



» ' Journal of the Society of Arts,' Marcli, 1878. 



