A CONTRIBUTION TO THE BIOLOGY OF BACTERIA. 201 
operation with ammoniated air above mentioned. Here the 
rosolic-acid cotton plug was not reddened, no free ammonia 
reaching the chambers. As a control experiment, the same fluids 
were added to solutions contained in test tubes, and which 
swarmed with organisms. No diminution in the violent move- 
ments of the Bacteria ensued, nor was their number apparently 
diminished. It is clear, therefore, that the vapours of these 
so-called antiseptic agents were not the cause of the retardation 
in the development or multiplication of organisms. That the 
organisms appear at all, but only comparatively late, is easily 
understood when it is borne in mind that Cohn observed in a 
simple solution of milk sugar a multiplication of Bacteria which 
derived their nitrogen, according to his hypothesis, from the 
atmosphere, to which fact I have already called attention, whilst 
Schonbein found that when water evaporates in atmospheric air 
nitrogen is made free. 
The success in practice of the treatment of wounds according 
to Mr. Lister^s method is now very generally admitted, but the 
hypothesis on which this method is based is not so universally 
accepted. My experiments are, in this respect, of some interest, 
but I am not willing to claim for their results any very general 
application. Observers of high rank still assert, after careful 
researches, the ubiquity of organic germs, and it is clear that 
such a view cannot be logically made to harmonise with the views 
held by Mr. Lister and his more ardent disciples. 
The antiseptic properties of the substances which I have used 
being conceded, I hold that they are harmful to the development 
and multiplication of organisms from the readiness with which 
they unite with substances indispensable to the existence of the 
organisms rather than on account of their direct antizymotic pro- 
perties. I freely grant that these researches do not conclusively 
])rove this supposition, but they seem to indicate such a relation. 
