169 



port germination. This supposition was rendered 

 the more probable, because he found, that when oxy- 

 gen gas was mixed with nitrogen thus saturated 

 with carbon, carbonic acid was formed, although 

 the two gases had, previous to their mixture, been 

 carefully washed in lime-water *. 



1 34. That the carbon of the seed had really esca- 

 ped, and combined with the nitrogen gas in the ex- 

 periments above stated, is farther evinced by what 

 follows. M. Huber prepared an artificial atmosphere 

 in proportions similar to that of common air, but in 

 which hydrogen was substituted for nitrogen gas : 

 and in this atmosphere he caused successive quanti- 

 ties of lettuce-seeds to germinate, till they ceased 

 any longer to grow. He then carefully washed this 

 mixture of gases in lime-water, until it produced not 

 the slightest discolouration ; and, when all the car- 

 bonic acid was by this means removed, he added to 

 the residue a portion of oxygen, previously deprived 

 of every particle of carbonic acid, and inflamed the 

 mixture in Volta's eudiometer over lime-water. At 

 the moment of inflammation, the lime-water was 

 rendered very turbid, and a great precipitation of 

 carbonate of lime took place. As no carbonic acid 

 existed in the two gases previous to their inflamma- 

 tion, its production must have arisen from that pro- 

 cess ; and we must therefore admit, that the carbon 

 which had combined with the hydrogen during ger- 

 mination was again separated from it, and had uni- 

 ted with the oxygen gas to form the carbonic acid 



* Mem. sur la Germination, p. 41. et seq. 



