FERMENTS, FERMENTATIONS, AND LIFE. 267 
organic matter. Pasteur has thus far met this argument 
only by the evidence of his experiments which prove that, 
in contact with purified air, neither fermentations nor putre- 
factions are possible. That is strictly sufficient, but we can 
go further. It is by no means a sure conclusion that these 
germs do not exist, because many of them are invisible 
under the lens. To begin with, we do note with certainty 
a certain number of species in atmospheric dust. It is 
therefore an admissible presumption that, if the remaining 
ones elude our eyes and our microscopes, that merely proves 
them to be smaller than the observed ones. But, perhaps, 
the problem ought to be viewed in a different way. We 
believe that these visible germs are the exceptions, that is, 
that they are beings already arrived at a certain degree of 
development, and that, in reality, all true germs are of 
dimensions forever beyond the reach of microscopic obser- 
vation, even conceiving lenses to be immensely more pow- 
erful than they now are. The microscope barely brings 
within our range of vision points that measure at least a 
ten thousandth part of a millimetre. The primitive germs 
of life cannot even approach the hundred thousandth part 
of a millimetre. Physics and metaphysics both assure us 
that we must here give up the hope of measuring and 
estimating things according to the powers of our limited 
senses. An effort is needed to pursue with the mind’s eye 
these perpetually-dwindling dimensions, still to go on 
though the imagination fails in the task, and to realize at 
last how far removed are the bounds of the microcosm. If 
the faculty of reaching out beyond the limits of our nature, 
which is one of the noblest prerogatives of our intelligence, 
does not desert us, we attain to the idea of the vital monads 
of Leibnitz, the organic molecules of Buffon, the compre- 
hension of existence for primal organisms diffused through- 
out the world by myriads of myriads, and the conception 
of the infinitely minute within the infinitely minute. 
