32 GERMINATION OF THE SEED. CHAP. f. 



inferred that a portion of oxygene gas had been 

 actually assimilated to the substance of the seed. 

 But if the two quantities proved to be constantly 

 equal, then it was to be inferred that the oxygene 

 gas had not been assimilated to the substance of 

 the seed, but only employed for the purpose of 

 abstracting from it part of its carbon in the forma- 

 tion of carbonic acid gas.* 



It was obvious that the ascertaining of the respec- 

 tive quantities must have given much elucidation to 

 the subject ; and the difficulty of ascertaining them 

 seemed not to be great. Lavoisier had discovered 

 that oxygene in combining with carbon by conbus- 

 tion undergoes no perceptible alteration of volume, 

 and that 100 cubic inches of carbonic acid gas con- 

 tain 98 cubic inches of oxygene gas. But the result 

 of combination from germinating seeds must be 

 precisely the same as from combustion ; it was 

 easy therefore to ascertain the quantity of oxygene 

 extricated along with the carbonic acid. Accord- 

 ingly M. Saussure instituted a set of experiments 

 to ascertain the proportion between the quantity 

 of oxygene inhaled and the quantity evolved in 

 the carbonic acid. The grains or seeds employed 

 were those of Peas, Beans, Barley, Lettuce, and 

 Cress, and the issue was as follows : In an at- 

 mosphere of 100 cubic inches of common air, 

 known to contain about 21 cubic inches of oxygene, 

 and 79 of nitrogen, when a number of these seeds 

 * Sur. la Yegct. chap. i. sect, ii. 



