THE THERMAL DEATH POINT OF BACTERIA I I/ 



At the next exercise examine the heated tubes and note 

 which are clear and which contain a growth. If the tubes 

 heated for 10 minutes or longer have a growth, repeat the 

 experiment at 70 C. If this fails to destroy them, repeat at 

 80 C., and if necessary apply a still higher temperature. 



Examine the cultures microscopically in all the fertile tubes 

 to determine if they are pure. 



Explain the cause for the difference in the thermal death 

 point between these two organisms. 



Examine the cultures made from the scrapings of the skin 

 in the previous exercise. 



