150 PROCESS OF NUTRITION. CHAP. III. 



air and carbonic acid gas the eudiometer indicated 

 .jSjiy-of oxygene ; and lime water 7? of carbonic 

 acid gas. Into the receiver containing this at- 

 mosphere there were introduced several plants 

 of the Vinca minor ; the apparatus was exposed 

 during six days to the direct rays of the sun, from 

 five o'clock in the morning till eleven. On the 

 seventh day the plants were taken out ; they had 

 undergone no alteration, nor had their atmosphere 

 sustained any perceptible change of volume. But 

 the lime water gave no longer any indication of the 

 presence of carbonic acid gas, and the eudiometer 

 indicated 24- 5 parts in the hundred of oxygene. 

 The capacity of the receiver was 2QO cubic inches ; 

 it contained, therefore, before the experiment 31 1 '0,2 

 inches of nitrogene, 56*33 of oxygene, and 2175 

 of carbonic acid. But after the experiment it was 

 found to contain 218'95 cubic inches of nitrogene, 

 and 71*05 of oxygene, which were the whole of its 

 contents ; the carbonic acid gas had disappeared. 

 The plant then had decomposed or elaborated 21 

 cubic inches of carbonic acid gas. Now, if in the 

 process of decomposition the whole of the oxygene 

 had been disengaged, there would have been also a 

 quantity of oxygene produced equal in volume to 

 the carbonic acid that had disappeared ; but the 

 quantity of oxygene disengaged was only 14-f- cubic 

 inches, The plants then had assimilated seven 

 cubic inches of oxygene in decomposing the car- 

 bonic acid ; and had at the same time produce^ 



