158 THE FLOATING-MATTER OF THE AIR. 



§ 9. Infusions of Fungi, 



Turning from hay to substances in which germs, if 

 they existed, could not be desiccated, I felt pretty sure 

 that infusions of such substances would be unable to 

 resist the boiling temperature. To test the correctness 

 of this view the following experiments were made : — 

 Three different kinds of fungi (red, black, and yellow) 

 were gathered in Heathfield Park on the 13th of Octo- 

 ber, and digested separately in London on the following 

 day. Three tubes of a closed chamber containing six 

 tubes were charged with the red-fungus infusion and 

 three with the black, while a second chamber of three 

 tubes was charged with tlie yellow-fungus infusion. 

 They were all boiled for five minutes after their intro- 

 duction into the chambers. 



For two or three days all the infusions continued 

 clear ; but they subsequently broke down, every tube 

 of the nine becoming turbid with organisms and covered 

 with scum. 



Examined microscopically on the 8th of November 

 the red-fungus infusion was found charged with a mul- 

 titude of spore-like bodies, massed in some places con- 

 tinuously together, in others floating freely in the liquid. 

 Among these ran long filaments, dotted with spore-like 

 specks from beginning to end. There was a consider- 

 able number of Vibrios in one of the tubes. The black- 

 fungus infusion contained a mixed population of Vibrios 

 and Bacteria with spore-filled filaments. Swarms of 

 Bacteria were observed in the red-fungus infusion. 



Suspicious of the chambers in which these infusions 

 had been exposed, I had three new ones constructed 

 and provided with new tubes. A fresh supply of fungi 

 was sent to me from Heathfield, a tree fungus being. 



