Prof. J. Le Conte on the Freezing of Vegetables. 197 
Experiment No. 2.—In the previous experiment, the lower 
extremity of the internode of elder was exposed to the action of 
the cold, and it might be supposed, that the frigorific influence 
was propagated along the stalk longitudinally, the direction in 
which the experiments of MM. Aug. De La Rive and Alph. De 
Candolle show, the conducting power of wood to be the greatest. 
For the purpose of obviating this difficulty, a hollow tin cylin- 
der, six inches in length, open at both extremities, was passed 
transversely through the centre of the opposite sides of a small 
wooden box. Another recently cut internode of elder was thrust 
through the cylinder, having both extremities projecting several 
inches beyond the ends of the metallic case, so that, only the 
middle portions would be subjected to the frigorific influence. 
On the 6th of Feb., 1851, at I o’clock p. m, the temperature of 
the room being 37° Fahr., the freezing mixture was introduced 
into the box. At the end of two hours,—the temperature of the 
mixture varying from 2° to 6° Fahr.,—the stalk was withdrawn 
for examination. The bark in the middle of the part which had 
been exposed to the cold, was found frozen as in the previous 
experiment; neither the bark, succulent zone, pith or w 
the extremities, exhibited any indications of congelation of the 
fluids contained in them. The middle of the stalk was then 
cut through by.means of a small saw which had been artificially 
cooled. On examining the transverse section, the liber and suc- 
ere, ; 
frozen,—a similar change, indicative of thawing, being clearly 
observable. “ 
«periment No. 3.—The foregoing experiments were tried on 
portions of plants which had been recently cut from the parent 
Stem or branch, and it might be imagined that the case would 
which had been planted in a large box of earth,—were, on th 
19th of Feb., 1851, submitted to experiment. The temperature 
of the room was 56° Fabr., the freezing mixture varied 
from 0° to 5° Fahr. Tin tubes were placed around haha 
the stems, so as to protect them from the immediate contact of 
