54 
fourth day; and at the period of investigation which was the same as the 
last, had made much less progress than in the oxygen gas. 
The air in the jar being examined, it was found to contain, 
1. Azotic gad, 
2. Carbonic acid gad', 
nearly in the proportion of one to two, mixed with a small quantity of 
oxygen gas, and but little of the barley tasted sweet. 
Being now satisfied that, during the evolution of the saccharine principle 
from vegetable mucilage, a quantity of oxygen was either absorbed or con¬ 
verted into carbonic acid, we wished to know if this process could take place 
in any degree without the presence of this gas. 
In order to determine this point, the following experiments were made. 
EXPERIMENT V. 
January 20th, a quantity of barley, soaked as in the former experiments, 
was introduced into a jar filled with and inverted over mercury. 
At the expiration of 12 days a very considerable quantity of gas was 
produced, at least five or six times the bulk of the barley; but nothing like 
vegetation wad perceived. 
The gas, on examination, was found to consist of carbonic acid , being 
entirely absorbed by lime-water. 
The barley had not the leadt dweet tadte , nor did it appear to have un¬ 
dergone any sensible change. 
EXPERIMENT VI. 
On January 20th, another portion of the same soaked barley was intro¬ 
duced into a wine glass, and placed in ajar containing nitroud gad,* inverted 
over water. 
At the expiration of 10 days the gas had undergone a slight diminution, 
but there was not the smallest appearance of vegetation. 
The barley being withdrawn and examined, was found to have undergone 
no apparent change. 
* account of the nature and formation of nitrous gas is given in note * page 50 . 
