642 FRAGMENTS OF 8CTKNCK. 
the others. The difference was extraordinary. The un- 
covered fruits had become soft, watery, and very sweet; 
the others were firm and hard, their fleshy portions being 
not at all watery. They had, moreover, lost a considerable 
quantity of their sugar. They were afterward bruised, 
and the juice was distilled. It yielded six and a half 
grammes of alcohol, or one per cent, of the total weight 
of the plums. Neither in these plums, nor in the grape 
first experimented on by Pasteur, could any trace of the 
ordinary alcoholic leaven be found. As previously proved 
by Lechartier and Belhtmv, the fermentation was the work 
of the living cells of the fruit itself, after air had been 
denied to them. When, moreover, the cells were destroyed 
by bruising, no fermentation ensued. The fermentation 
was the correlative of a vital act, and it ceased when life 
was extinguished. 
Liidersdorf was the first to show by this method that 
yeast acted, not, as Liebig had assumed, in virtue of its 
organic, but in virtue of its organized character. He 
destroyed the cells of yeast by rubbing them on a ground 
glass plate, and found that with the destruction of the 
organism, though its chemical constituents remained, the 
power to act as a ferment totally disappeared. 
One word more in reference to Liebig may find a place 
here. To the philosophic chemist thoughtfully pondering 
these phenomena, familiar with the conception of molecular 
motion, and the changes produced by the interactions of 
purely chemical forces, nothing could be more natural 
than to see in the process of fermentation a simple illus- 
tration of molecular instability, the ferment propagating 
to surrounding molecular groups the overthrow of its own 
tottering combinations. Broadly considered, indeed, there 
is a certain amount of truth in this theory; but Liebig, 
who propounded it, missed the very kernel of the phe- 
omena when he overlooked or contemned the part played 
in fermentation by microscopic life. He looked at the 
matter too little with the eye of the body, and too much 
with the spiritual eye. He practically neglected the 
microscope, and was unmoved by the knowledge which its 
revelations would have poured in upon his mind. His 
hypothesis, as I have said, was natural nay it was a strik- 
ing illustration of Liebig's power to penetrate and unveil 
molecular actions; but it was an error, and as such has 
