BOTANY. 329 



ON THE FREEZING OF VEGETABLES AND PLANTS. 



FROM an interesting paper submitted to the American Association, 

 Albany, on the above subject, by Prof. J. Leconte, we make the follow- 

 ing extracts : 



The author commences by citing the opinion of John Hunter, before 

 the Royal Society, in 1775, that animals must be deprived of life before 

 they can be frozen ; and that plants must be deprived of the principle of 

 vegetation before they can be frozen. But these generalities have been 

 since contradicted, for Sir John Franklin, and others, have noticed that 

 fishes and reptiles have been found in a frozen state, and have afterwards 

 been restored to life. If this generalization is inapplicable to animals, it 

 might naturally be expected that plants, in which the functions of 

 vitality are still more obscurely manifested, should be endowed with 

 the power of resisting cold in a greater degree. Yet writers on vege- 

 table physiology seem to be very generally decided that " the complete 

 solidification of the fluids of a plant must necessarily and inevitably 

 result in its death." In corroboration of the opinions above stated, the 

 author cites Decandolle, Prof. Henslow, &c. Modern vegetable physi- 

 ologists have been so impressed with the fundamental idea of Hunter, 

 that they have rather sought for causes which might prevent the juices 

 of plants from freezing, then endeavored to overthrow the principle 

 which they thought established. 



Prof. Leconte stated that, until quite recently, he had participated 

 in this fundamental opinion, and that when he commenced his inves- 

 tigation, all his prepossessions were in favor of the theory already es- 

 tablished. But from the examinations made during the winter of 

 1850-51, he had become satisfied that plants might be frozen without 

 the slightest injury. During that winter he had noticed roses, pines, 

 and other plants, which had become frozen so that they snapped ofl' 

 like pipe-stems, yet they were uninjured by this intense freezing. After 

 making a series of experiments on plants, such as the elder, with consid- 

 erable pith, and which it might be supposed extreme cold would affect 

 readily, he was forced to the conclusion that freezing has little or no effect 

 on them. Instances were cited where trees have been known, as in Hud- 

 son's Bay, Canada, and Maine, to have been frozen so that the physical 

 qualities of the wood appeared to be altered, yet still the trees lived 

 and throve with unabated vigor on the return of warm weather. The 

 observations of Ernian, Von Humboldt, and others, have abundantly 

 proved, that in Siberia the ground is frozen to a great depth, so that 

 even the fibres of the roots and the roots themselves must be a solid 

 icicle. Indeed, the larches in Siberia not only have their roots resting 

 on a frozen substratum all the year round, but are themselves frozen 

 for nearly eight months in the year. Nor are these facts confined to 

 the larch forests of Siberia. Large portions of both Europe and North 

 America, lying north of the isothermal line of 32 Fahr., support ex- 

 tensive forests of birch, spruce, larch, Scotch fir, &c., where the ground 

 ice is perpetual. 



It may be objected to this that trees are known to split with the cold. 

 To this it may be remarked, that young trees are hardly ever known 



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