CH. I.] 



SOWING. 



19 



treated. This acceleration of vegetation continued 

 equally marked throughout their growth, and is 

 further explained hy other experiments of M. 

 Schluber, which testify that those soils in the above 

 table which absorbed the heat most readily, retained 

 it most tenaciously, and consequently were longest 

 coohng. Magnesia cooled in one hour and twenty 

 minutes as much as the garden mould did in two 

 hours and sixteen minutes, and the slaty marl in 

 three hours and twenty-six minutes. 



From more recent experiments made in the Hor- 

 ticultural Society's garden at Chiswick, and in other 

 parts of England, Ave have the following results, con- 

 firming M. Schluber's experiments. 



In the Chiswick garden, 



In a stiffish loam on a gravelly subsoil near 

 Sheffield, after a fortnight "s exposure to a minimum 



c 2 



