Prof. J. Le Conte on the Freezing of Vegetables. 203 
producing openings many yards long and ten or twelve inches 
wide. Such phenomena cannot be ascribed to the expansive 
power of freezing water, because they occur during mid-winter, 
and in latitudes where the rigor of the:climate is such, that the 
earth is frozen 300 or 400 feet deep, (certainly far below the 
depth of these superficial fissures,) long before these effects are 
observed. They are unquestionably the. tesult of superficial 
sufficient intensity to maintain water in a solid condition for any 
Considerable portion of the winter. ‘The cracking always takes 
place during periods of rapid augmentation of cold. ‘To those 
who may be incredulous as to the adequacy of superficial con- 
traction to produce the observed effects, it may be proper to state, 
that according to the experiments of MM. Brunner and Schu- 
macher, the contraction of ice consequent upon a diminution of 
temperature, is greater than that of any other solid body hitherto 
examined. The former found the amount of linear contraction 
* Erman’s Travels in Siberia. Ed, cit. ante, vol. i, p. $81, et vol. iy p. 218. 
‘gif Vide Ann. de Chim. et de Phys, ad series, vol. xiv, p. 869-1849, a8 cited in 
Silliman’s Journal, 2d series vol. i, p. 117—1846; also vol. iii, p. 450 of 
—_ : er, MM. Pohrt and 
Moritz haye found the linear expansion of ice for an interval plone od eo the 
scale, to be 0 
of 
chumach: xperiments. (Vide Liebig and K ’s Report on the 
igh saree tisluntcn or Ce. *FEondon, 1849.) 
44, 
