FRANZ SCHULTZE'S EXPERIMENT. 



Nevertheless, the supporters of the spontaneous generation 

 theory were still far from regarding their cause as lost. They 

 characterised these experiments as inconclusive, since (so they said) 

 "by the immoderate heat Spallanzani chose to employ, the air in 

 the vessel is so unfavourably changed, and rendered so unsuitable 

 for the maintenance of life, that it is no occasion for surprise that 

 all development was lacking." This objection was curtly rejected 

 by Spallanzani, but an experimental confutation was only arrived 

 at much later. The next step in this direction was accomplished 

 in 1836 by 



5. Franz Sehultze's Experiment. 



In order to avoid under-estimating the value of the very short 

 treatise (I.) published by this investigator, regard must be had 

 to the influence attained by Chemistry in all branches of natural 

 science during 

 the sixty years 

 that had elapsed 

 since Spallan- 

 zani's demonstra- 

 tion, an influence 

 which will be 

 elucidated, in so 

 far as it refers 

 to the theory of 

 Fermentation, in 

 subsequent sec- 

 tions. The idea 

 that ordinary air 

 acts as an inducer 



of fermentation or putrefaction by reason of its content of living 

 germs was first called into existence by Schultze. 



He described his experiment as follows : "I filled a glass flask 

 half full of distilled water (Fig. i), with which I had mixed various 

 animal and vegetable substances, and closed it with a sound cork, 

 through which were passed two tight-fitting glass tubes bent to 

 elbow joints. I next placed it in a sandbath and applied heat 

 until the water boiled briskly, so that all parts were exposed to a 

 temperature of 100 C. Whilst the hot water vapour was still 

 issuing from the two tubes, I attached to the end of each an 

 apparatus employed by chemists, in the course of organic analyses, 

 for the absorption of carbon dioxide. That on the left-hand side 

 was filled with concentrated sulphuric acid, the other with a solu- 

 tion of potassium hydroxide." After cooling the apparatus, air 

 was drawn through twice every day during the ensuing two 

 months, in such a manner that it had to pass through the sulphuric 

 acid before entering the flask. The results confirmed the expecta- 



FiG. i. Franz Sehultze's Experiment. 



