29 
solution. Further, the production of fermentation is connected 
in some way with the vital processes of life and reproduction 
of the fungus. Probably the peculiar power which the plant 
has of seizing some of the elements of the sugar and appro- 
priating them for its own growth, may in some way set up 
the chemical changes. The activity of the fermentation is 
directly proportionate to the rapidity of growth of the plant, and 
conditions which destroy its life deprive it of its power of fermen- 
tation. Independent of the Torula, fermentation does not occur ; 
a saccharine solution will not ferment spontaneously. If it begins 
to ferment, yeast has undoubtedly got into it in some way or other. 
If it is boiled so as to destroy the efficiency of any yeast germs it may 
actually contain, and then allowed to come into contact only with 
such air as has been passed through cotton wool (which has the 
power of intercepting any germs floating in that medium) it will 
never ferment. 
The chemical changes of putrefaction are intimately associated 
with the growth of minute living organisms, known as bacteria or 
microzymes. How far the microzymes are the cause of the 
-chemical changes which are coincident with their evolution it is 
difficult to say. It has been demonstrated that many animal - 
fluids show no little disposition to putrefy so long as the germs 
of microzymes are excluded, but that the putrefaction is at once 
excited by their access ; therefore, under certain circumstances, 
it may be said that microzymes are the cause of putrefaction, and 
__ experience shows this to be the rule. Putrefaction does not occur 
spontaneously, but it is set up by the germinal matter of micro- 
zymes, and its. progress is accompanied by their growth and 
reproduction. Having defined the terms bacteria, or microzymes, 
Dr. Philpot continued—From careful examination it seems probable 
_ that bacteria came into distinguishable existence as spheroids. 
What are the conditions of their origin? There being an immense 
3 preponderance of evidence that they do not spring into existence 
of themselves in the media in which they grow, most observers 
have looked for germs in the atmosphere, but with no success. 
Liquids which contain no particle distinguishable under the highest 
powers of the microscope can often be proved to possess the 
property of evolving microzymes without contact with external 
media, and must, therefore, contain the germinal substance from 
_ which these organisms spring. In interpreting this fact it may be 
supposed that the germinal substance is universally and equally 
distributed, ¢.e., dissolved in such liquids, or that it is unequally 
distributed or particulated. That any living substance is soluble 
in water, is not at present admissable; we must therefore accept 
_ the other alternative, and believe that we have to do with particles 
m. . minute that they do not interfere with the homogeneity of the 
iquid. 
