224 
proving the volatilization of the lime *. We have 
seen, too, the deleterious effect which mercury, in a 
similar manner, produces (3 1C.); and this mode of 
explaining the fact furnishes a reason why the death 
of the plants happened only in sunshine, since the 
lime, in that situation, was much more readily vola- 
tilized. 
505. In the foregoing experiments, the roots of 
the plants were immersed in pure water, but, in sub- 
sequent trials, M. de Saussure operated on the bran- 
ches of a tree, whose roots were growing in the earth. 
Into a glass balloon, of the capacity of 20O cubic in- 
ches, he introduced an ounce of lime, and, to remove 
all objection respecting its property of attracting 
moisture, he lightly moistened it with water. A branch 
of honeysuckle, or of the peach, furnished with 
leaves, was then passed into the balloon, and so dis- 
posed that its leaves should neither touch the lime, 
nor the sides of the vessel.. The neck of the balloon 
was then carefully luted to the branch, and the appa- 
ratus was exposed to the sun. The leaves of the 
branch continued green twelve days, when they be- 
gan to dry, and at the end of three weeks they had all 
fallen. The branch, however, did not die ; but in a 
month after, while retained in the balloon, which still 
remained closed, it put forth new leaves. A similar 
branch, introduced into another balloon, and placed in 
the same circumstances, but without lime in the vessel, 
preserved its freshness for more than two months. The 
* Nicholson's Journal, vol. xviii. p. 22. 
