On the Action of Heat on Protoplasmic Life. 133 



The results recorded in the above Tables show that protoplasmic 

 life is but slightly affected by a temperature of 212° F., and that even 

 at a temperature of 300° F. it is not entirely destroyed, excepting 

 in the case of gelatine. In all the other fluids a temperature of 

 400° F. is necessary to completely destroy the life. These experi- 

 ments, therefore, clearly show that the life found by previous experi- 

 menters in fluids which have been submitted to heat was not due 

 to heterogenesis, but to life which had remained in the fluids, as I 

 have seen no experiment reported where the temperature to which 

 the fluids were exposed exceeded 300° F.* 



I am the more justified in making this statement, as I have re- 

 peatedly examined the contents of tubes which had been submitted 

 to a temperature of 400° F., both immediately after cooling and at 

 all periods up to thirty days, and was unable in any instance to detect 

 the slightest trace of life. 



This important result corroborates those recorded in my previous 

 paper, and proves that the spontaneous-generation theory is not yet 

 by any means established. 



It occurred to me that it might be interesting to examine the in- 

 fluence on pure albumen of the putrid-meat fluids that had been 

 heated, and note whether they still possessed the property of propa- 

 gating life. A solution was prepared by mixing the albumen of a 

 new-laid egg with pure distilled water free from life (prepared as de- 

 scribed in my previous paper). Equal volumes of this solution were 

 placed in six small test-tubes, which had been cleansed with hot vitriol 

 and well washed with pure water. To one tube two drops were added 

 of the putrid-meat solution that had been heated to 100° F., to 

 a second two drops of that heated to 212° F., to a third two drops 

 of that heated to 300° F., to a fourth an equal bulk of fluid heated to 

 400° F., and to a fifth the same quantity heated to 500° F. In the 

 sixth the albuminous solution, without any thing added, was kept for 

 comparison. 



The tubes were sealed, and kept from the 1st of February to the 

 9th. 



Results of Examination. 



Albumen 

 solution. 



In each drop 

 2 or 3 small 

 black vibrios, 

 moving to and 

 fro. 



Albumen so- 

 lution, with 

 putrid-meat 

 liquor, heated 

 to 100° F 



Abundance 

 of life. 



Albumen so- 

 lution, with 

 putrid-meat 

 liquor, heated 

 to 212° F, 



Abundance 

 of life. 



Albumen so- 

 lution, with 

 putrid-meat 



liquor, heated 

 to 300° F. 



Much less life 

 than in the 

 two fluids pre- 

 viously exa- 

 mined. 



Albumen so- 

 lution, with 

 pvitrid-raeat 

 liquor, heated 

 to 400° F. 



In each drop 

 2 or 3 small 

 black vibrios, 

 moving to and 

 fro. 



Albumen so- 

 lution, with 

 putrid-meat 

 liquor, heated 

 to 500° F. 



In each drop 

 2 or 3 small 

 black vibrios, 

 moving to and 

 fro. 



* It is with pleasure that I find these experiments to confirm the suggestion 

 of Dr. Beale, in his work entitled " Disease-Germs, their supposed Origin," 

 page 50 (which I read a few weeks ago), that " living forms might live though 

 exposed, under certain conditions, to a temperature of 350° F." 



