On the Heat necessary to kill Bacteria, Vibrioses, fyc. 325 



" Further Observations on the Temperature at which Bacteria, 

 Vibriones, and their Supposed Germs are killed when exposed 

 to Heat in a moist state ; and on the Causes of Putrefaction 

 and Fermentation/'' By H. Charlton Bastian, M.A., M.D., 

 F.R.S., Professor of Pathological Anatomy in University 

 College, London. Received March 2o, Read May 1, 1873. 



Whilst a heat of 140° P. (60° C.) appears to be destructive to Bacteria, 

 Vibriones, and their supposed germs in a neutral saline solution, a heat of 

 149° or of 158° F. is often necessary to prevent the occurrence of putre- 

 faction in the inoculated fluids when specimens of organic infusions are 

 employed. What is the reason of this difference ? Is it owing to the 

 fact that living organisms are enabled to withstand the destructive in- 

 fluence of heat better in such fluids than when immersed in neutral saline 

 solutions ? At first sight it might seem that this was the conclusion to 

 be drawn. We must not, however, rest satisfied with mere superficial 

 considerations. 



The problem is an interesting one ; yet it should be clearly understood 

 that its solution, whatever it may be, cannot in the least affect the vali- 

 dity of the conclusion arrived at in my last paper, viz. that living matter 

 is certainly capable of arising de novo. We were enabled to arrive at 

 the conclusion above mentioned regarding Archebiosis by starting with 

 the undoubted fact that a heat of 158° F. reduces to a state of potential 

 death all the Bacteria, Vibriones, and their supposed germs which an or- 

 ganic infusion may contain. The inquiry upon which I now propose to 

 enter, therefore, touching the degree of heat below tliis point which may 

 suffice to kill such organisms and their supposed germs in an organic 

 infusion, and touching the cause of the delayed putrefaction apt to take 

 place in inoculated organic infusions which have been heated to tempe- 

 ratures above 140° and below 158° F., is one lying altogether outside the 

 chain of fact and inference by which the occurrence of Archebiosis is 

 proved. 



It seems to me that the solution of the problems which form the sub- 

 ject of the present communication can only be safely attempted by 

 keeping constantly before our minds two main considerations : — 



Thus, in the experiments whose results it is now our object to en- 

 deavour to explain, the fluids have been inoculated with a compoun 

 consisting partly {a) of living units, and partly (b) of a drop of a solu- 

 tion of organic matter in a state of molecular chauge ; so that in many 

 cases where putrefaction has been iuitiated after the inoculating com- 

 pound has been heated to certain temperatures, there is the possibiliy 

 that this process of putrefaction may have been induced (in spite of the 

 death of the organisms and their germs) owing to the influence of b, the 

 dissolved organic matter of the inoculating compound; that is tosay 



vol . xxi. 2 E 



