13 . 



11. That the whole loss of bulk which the air 

 suffered in the foregoing experiments, did actually 

 arise from the formation of carbonic acid, and its 

 subsequent attraction by the alkaline solution, ap- 

 pears almost certain, from the opposite results ob- 

 tained when no such solution was employed. In 

 the experiment of Mr Cruickshank, (6.), made in 

 pure oxygen gas, the original" volume of gas suffer- 

 ed neither increase nor diminution, although it was 

 almost entirely converted into carbonic acid ; and 

 the same observation was made in all the experi- 

 ments of Saussure. In a great number of experi- 

 ments also, we observed, that where no water of 

 potassa was placed within the jar, the seeds equally 

 grew ; the oxygen gas was completely destroyed, 

 and the residual air lost about l-5th of its bulk by 

 agitation in lim^-water, although the volume of air 

 was only in a small degree diminished. This trifling 

 diminution was probably owing to the necessary 

 condensation which oxygen gas experiences when 

 it combines with carbon, and which, according to 

 Crawford and Guyton, amounts to about l-7th of 

 the bulk of gas employed % although it is probable 

 that this estimate is considerably overrated. 



12. We endeavoured to ascertain the amount of 

 this diminution in germination, by causing some 

 soaked peas to grow, supported on a whalebone 

 hoop, in a small flask with a narrow neck, which 

 was inverted into an ale-glass containing mercury. 

 When the peas had ceased to grow, the rise of the 



Murray's "System of Chemistry, vol. ii. p. 352. 



