396 THE BEGINNINGS OF LIFE. 



group at the same time, and were, thenceforward, 

 subjected to the same temperature. The results were 

 as follows : After twenty-four hours the slightly alkaline 

 fluid which had been boiled showed a slight though 

 decided opalescence; it was, in fact, very similar in 

 appearance to the acid solution which had not been 

 boiled. The boiled acid solution was, however, as 

 clear as when the flask was first suspended, and it 

 remained apparently quite unaltered, after it had been 

 suspended a week j though the boiled alkaline solution 

 had by this time become decidedly opaque, and also 

 showed some flocculent matter lying at the bottom of 

 the vessel. And after they had been suspended rather 

 more than three weeks, the acid solution still remained 

 almost transparent, presenting only the faintest cloudi- 

 ness, though with no pellicle or deposit at the bottom 1 . 

 The boiled alkaline fluid, however, exhibited a totally 

 different appearance ; it was whitish and quite opaque, 

 there was a very thick pellicle covering part of its 

 surface, and also some whitish sediment at the bottom 

 of the flask. 



Thus the difference which already exists between 

 alkaline and acid solutions at ordinary temperatures was 

 seen to be most notably intensified after similar alkaline 

 and acid solutions have been raised to a temperature of 



1 This solution was, therefore, much more backward in exhibiting 

 signs of change than were the others which had been used in Experi- 

 ments 2 to 5 a difference probably explicable by the poorer quality of 

 the turnip used in this last experiment (see p. 394, note i). 



