CHAPTER V 



CONCERNING THE EXPERIMENTAL CONDITIONS, THE 

 NATURE OF THE ORGANISMS FOUND IN THE 

 TUBES, THEIR CULTIVATION AND THEIR THER- 

 MAL DEATH-POINT 



LITTLE requires to be said concerning the experi- 

 mental conditions beyond what has already been 

 stated. 



After the process of heating, the tubes were 

 cleaned, labelled, and exposed to diffuse daylight 

 at the end of an open north balcony facing the 

 east. There they remained all through the winter, 

 and most of them for nine to twelve months, till, 

 day by day, one was opened for examination of 

 its contents. 



In the month of April, however, a few of the 

 tubes were brought indoors, and placed just in- 

 side a south window, where they were left for five 

 or six weeks before they were opened. I was in- 

 duced to take this step because I had found, rather 

 to my surprise, that in some of the tentative ex- 



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