23 * 
tirely of an herbaceous nature, we next procured a 
young willow plant, about 14 inches high, the stem 
and greater part of whose branches were of a firm, 
and woody texture. It grew in a garden pot, and a 
tin dish, of a large size, was adjusted to it, in the 
manner already related. On the 28th of July, a bell 
shaped jar, of the capacity of 250 cubic inches, was 
inverted over it, the mouth of which was, as usual, 
surrounded with water. The apparatus was set aside 
in a room, in full day light, but not exposed to the 
sun, where the temperature, through the day, varied 
from 60 to nearly 70. The plant looked quite fresh 
and in a growing state for a few days, but on the 
31st, two of its leaves fell off, and, by the 3d of Au- 
gust, nearly half its leaves had fallen. Apprehensive 
that if the leaves were suffered to remain within the 
jar, decomposition might ensue, and disturb the na- 
tural result, we removed them by immersing the 
whole apparatus in a deep trough of water, and then ' 
cautiously raising the jar, we drew away all the fallen 
leaves under water, without permitting any fresh air 
to enter. At the same time, a small quantity of the 
air of the jar was passed into another jar, and was af- 
terwards found, on analysis, to contain no carbonic 
acid, but it lost -rW by the slow combustion of phos- 
phorus. The apparatus was afterwards replaced in 
its former situation. 
231. During the following days, the leaves conti- 
nued to fall, and by the 6th of August, few remained 
on the branches j the plant, however, in other re- 
spects, looked healthy, and had grown about an inch. 
We now again removed the fallen leaves as before. 
