$0 TERMINATION OF THE SEED. CHAP. I. 



the seed already contains ; or, does it form a com- 

 bination with the substance of the seed, and 

 identify itself with the germinating embryo? Or, 

 does it abstract from the seed any particular princi- 

 ple of its composition, and so effect the change that 

 follows ? The suppositions contained in these ques- 

 tions have each had their defenders and opponents ; 

 though there is now, as I believe, but one opinion 

 on the subject. 



According Humholdt thought that the oxygene acts merely 

 " 11 as a stimulant ; and his opinion was founded upon 

 the fact that seeds germinate faster, as it appeared, in 

 pure oxygene gas than in common air ; but particu- 

 larly when steeped in water impregnated with oxy- 

 muriatic acid, according to his own discovery. But 

 this conclusion, though sufficiently plausible at first 

 sight, is by no means sufficiently warranted by the 

 premises. In pursuit of facts, however, to esta- 

 blish and confirm it, Humboldt was fortunate 

 enough to stumble upon discoveries of some im- 

 portance. He found that seeds brought both from 

 the East and West Indies, which had constantly re- 

 fused to germinate at Vienna, germinated very 

 readily when treated with oxy muriatic acid, even 

 after having been kept for a period of from twenty 

 to thirty years. This fact seemed extremely 

 favourable to his opinion, and contributed no doubt 

 to give it a considerable currency at the time, which 

 on some part of the Continent perhaps it still re- 

 tains, as we find his conclusion to have been adopts 



