322 THE BEGINNINGS OF LIFE. 



In order still further to test these views, I took an 

 infusion of turnip, containing a multitude of Bacteria, 

 whose movements were of the languid description, and 

 divided it into two portions. One of these portions 

 was boiled for about one minute, whilst the other was 

 not interfered with. After the boiled solution had been 

 cooled, a drop was taken from each and these were placed 

 at some little distance from one another on the same 

 glass-slip; covering-glasses half an inch in diameter 

 were laid on, and the superfluous fluid from beneath 

 each of them was removed by blotting-paper. When 

 only the thinnest film of fluid was left, the covering- 

 glasses were surrounded by a thick, quickly-drying 

 cement 1 . Examined with the microscope immediately 

 afterwards, it was generally found that the Bacteria 

 which had been boiled presented a shrunken and 

 shrivelled aspect whilst some of them were more or 

 less disintegrated though, as far as movement was 

 concerned, there was little to distinguish that which 

 they manifested from the slight oscillations of their 

 unboiled and plumper-looking relatives. 



If the specimens were examined again after twenty- 

 four or more hours, there was still very little difference 

 perceptible between them as regards their movements. 

 And the same was the case when the specimens were 

 examined after a lapse of some days or weeks. One 



1 I always employ a solution of gum mastic and bismuth in chloro- 

 form. If a different varnish be employed, it is of course necessary to 

 ascertain that its application is not injurious to the enclosed Bacteria. 



