372 THE BEGINNINGS OF LIFE. 



was seen actively moving from end to end of the 

 cell. 



'Experiment 6. A flask containing a saturated solution 

 of ammonic tartrate and sodic phosphate, prepared in 

 the same manner as the last solution and at the same 

 time, though opened on the thirty-fifth day, yielded 

 no organisms of any kind. 



Experiment 7. A closed flask containing a solution 

 of ammonic acetate and sodic phosphate was opened 

 forty-two days after it had been hermetically sealed. 



The solution during this time had shown no signs of 

 deposit, turbidity, or pellicle, and on microscopical 

 examination of the fluid, no organisms of any kind were 

 discovered. 



All the fluids in the experiments hitherto related were 

 subjected to a temperature of 2i2F. It has been pre- 

 viously ascertained that none of the lower organisms 

 which had been so treated and afterwards examined were 

 able to survive an exposure for a few seconds to such a 

 degree of heat. They had nearly all been destroyed, in 

 fact, at a temperature many degrees short of this 1 . Many 

 different kinds of organisms have been submitted to 

 this test, and without the occurrence of any exceptions 2 



1 See pp. 3^5-336. 



2 No exceptions, that is, amongst such organisms as are met with in 

 infusions. The only known exceptions to that rule being met with in 

 the case of seeds, naturally provided with a hard testa, which had under- 

 gone an extreme amount of desiccation (see p. 314, note i). 



