14 Proceedings of the Royal Physical Socrety. 
all altered in its composition by passing through the sulphuric 
acid in the flask; but if sufficient time was allowed for the 
passage, the portions of living matter, or matter capable of 
becoming animated, were taken up by the acid and destroyed. 
From May 28th till the beginning of August I continued 
uninterruptedly the renewal of the air in the flask, without 
being able, without the aid of a microscope, to perceive any 
living animal or vegetable substance, although during the 
whole of that time I made my observations almost daily on 
the edge of the lquid; and when at last I separated the 
different parts of the apparatus, I could not find in the whole 
liquid the slightest trace of infusoria, conferve, or of moulds ; 
but all three presented themselves in great abundance a few 
days after I had left the flask standing open. The vessel 
which I placed near the apparatus contained on the following 
day vibriones and monads, to which were soon added larger 
polygastria, infusoria, and afterwards rotatoria.” 
Schulze was thus able to prove that the sterility was not 
dependent upon any alteration in the air within the flask, or 
to the small quantity of air contained in it, and that it was 
not due to any alteration brought about in the liquid by the 
heating process, as on the one hand a large quantity of air 
was passing through the flask, whilst on the other the fluid 
that had been boiled, but which was left exposed, rapidly 
underwent decomposition, a decomposition that was accom- 
panied by the development of micro-organisms in very large 
numbers. 
The objection that some particles of sulphuric acid drawn 
in with the air might affect the growth of organisms was met 
by Schulze by further experiments; and Schwann, who, 
instead of using sulphuric acid, used heat as a means of 
destroying any particles that might be present in the air that 
was drawn into the flask, corroborated Schulze’s statements. 
Now came further objections from the supporters of 
abiogenesis, who stated most definitely and categorically 
that these workers were not dealing with germs at all, but 
simply with particles of albuminoid matter floating in the 
atmosphere, as a result of the vegetative power of which, 
organisms of various kinds, according. to the conditions by 
