io8 



THE SPIRIT OF THE SOIL 



plotted against time, the dotted line showing the 

 plants that had no Silver extract, and the unbroken 

 line those which received the extract: 



8-0 



7-0 



J 6-o 



4-0, 



10 zo 30 -i.o 

 Time in Ua.i;5 



This experiment, particularly when taken in con- 

 junction with the previous ones and others, proves 

 conclusively that bacterized peat contains a sub- 

 stance or substances which stimulate the growth of 

 the plant and enable it to utilize the normal food 

 constituents supplied to it. In nature the need 

 is doubtless supplied by the decaying organic 

 matter in the soil. 



As has been pointed out above, anti-scorbutic 

 vitamine is not present, so far as can be ascertained, 

 in dry seeds, but it makes its appearance two or 

 three days after the young roots have begun to show, 

 and extracts from them have proved as effective as 



