14 



mercury into the neck of the flask was accurately 

 marked, and the air was then analyzed. The de- 

 struction of its oxygen gas was found to be com- 

 plete, and the usual quantity of carbonic acid to be 

 formed. After deducting the space occupied by 

 the seeds and the hoop which supported them, the 

 volume of air, at the close of the experiment, was 

 compared with that which it possessed at the begin- 

 ning, and the difference noted. An estimate was 

 then made of the quantity of oxygen gas originally 

 contained in the air employed, and the loss of bulk 

 was considered to arise from the condensation at- 

 tending its conversion into carbonic acid, due atten- 

 tion being paid, at the same time, to corrections for 

 pressure and temperature. The average amount of 

 the diminution varied from 1-Sth to 1-1 2th ; or 

 the volume of carbonic acid produced was about 

 1-1 Oth less than that of oxygen gas which had dis- 

 appeared. In some trials the amount of the diminu- 

 tion was much greater, but this was found to depend 

 on the quantity of moisture given out by the seeds, 

 and the more or less vaporific state in which it ex- 

 isted, and which source of error can be obviated on- 

 ly by reducing the air to the same state with regard 

 to moisture at the end, as at the commencement of 

 the experiment. From the whole, however, we 

 may conclude, that a certain condensation attends 

 the conversion of oxygen gas into carbonic acid in. 

 the process of germination, as well as in combus- 

 tion ; and consequently that a part of the diminu- 

 tion which the air suffers, is to be attributed to this 

 cause. If this were not the case, the bulk of carbo- 

 nic acid produced would- appear greater than that of 



