I5S ACCOUNT OF BOORS. 



influence of air 

 in vegetation; 



Huber and Se- J * n azolc > were not affe&ed by a proper quantity of oxigeri 

 nebier on the being introduced by degrees, but (hot forth very well when 

 the fame quantity was introduced at once. This difference 

 may be explained by confidering, that in the full cafe the 

 oxigen is fuccellively employed in receiving from the grain 

 the carbon which is difengaged, lb that none remains to vi- 

 vify it, but when it is poured in at once, there is fufficient 

 for both purpofes. 



Seeds do not germinate either in carbonic gas, or pure hi- 

 drogen gas. One lettuce feed abforbs in order to germinate 

 a portion of oxigen, which is equal to 26 milligrammes of 

 water, (half a grain) and it does not grow unlefs the oxigen 

 is at leaft the eighth part of the atmofphere in which it vege- 

 tates. A great quantity of carbonic acid gas is more injurious 

 to germination than the azote, and the azotic gas more l"o 

 than hidrogen. 



If feeds be put to grow in hidrogen gas, the carbon of the 

 grains diflblves in it, and combines very intimately. 



The vapour of fulphuric ethep- placed under a recipient of 

 atmofpheric air, prevented the feeds from growing, without 

 altering the quantity of oxigen in the air. The fame happens 

 with camphor, oil of turpentine, afla-fcetida, vinegar and am- 

 monia. Putrefied bodies prevent germination, by the abun- 

 dance of car-bonie acid gas they emit. It appears from the 

 preceding fa6ts that oxigen is indifpeniibly neceflary to germi- 

 nation, and that it ierves to carry off from the grain that 

 carbon which is difengaged by fermentation. But this rule it 

 not without its exceptions. 



In fad peas have germinated in water deprived of air by 

 every poihble means, and at whatever depth they have been 

 immerled. The feeds of beans, lentilles, fpinach, lettuce and 

 corn, grow in the fame manner beneath the water with 

 greater or lefs facility. Thefe feeds germinate better in water 

 charged with oxigen gas, than in water entirely deprived of 

 it, but not at all in wafer charged with carbonic acid. The 

 acids relard their germination. The air emitted by peas un- 

 der pure water, is a mixture of carbonic acid and carbonated 

 hidrogen. 



Peas have germinated in pure hidrogen gas and in air, 

 where other feeds have already germinated, and they have 

 totally exhaufled the oxigen it contained. In this experiment 

 the hidrogen gas becomes loaded with carbon. They like- 

 wife 



