ACCLIMATING PLANTS. 73 



potash, and lime ; the first two pass off mostly as odorous gases. 

 How is it possible for frost to do this ? Boiling with sulphuric 

 acid at 213° ruptures the starch cells, sunders their contents, 

 which changes to dextrine, and then to sugar. The same results are 

 obtained by fermentation. We know that frost sunders the starch 

 cells. The wilted condition of the once frozen potato evinces 

 this, before we examine its contents. Who ever saw a mealy 

 potato, when it had been frozen before boiling ? It presents some- 

 what the appearance of one that has begun to sprout, but is 

 sweeter and less firm, showing the effect produced upon the starch. 

 Have we an}^ other example of such work b}"^ frost? 1 recalled to 

 mind that some seeds are said to germinate better, after exposure 

 to frost, and that some will not germinate without such exposure. 

 It is said that the oflflce of frost, in these cases, is to rupture or 

 soften the dry, hard pericarp, whose obduracy resists the warm 

 rains and moist earth, sometimes for more than a year. But let 

 the frost once exert its influence, and then, under a proper degree 

 of warmth and moisture, the seeds show a celerit}' of movement 

 only excelled by the progenitors of that troublesome insect the can- 

 ker worm, under like influence. I had tapped my maples for sap, 

 and the sugar came to mind, heretofore ascribed to the change in 

 cellulose, starch, and gum by dextrine, heat, and ferment. But 

 the sugar from the maple differs from the sugar of the potato, by 

 the equivalent of one half molecule of water, and the potato has 

 sixt^'-five per cent, of water to thirty-three or less, in the maple. 

 Would that account for the difference in the sugars? " The first 

 run of sap is sweetest." "The nearer the bark, the sweeter the 

 sap." " The farther from the ground, the sweeter the sap." 

 " Successive freezings give continuous supplies of sweet sap." All 

 these aphorisms of the sugar camp went through my mind. But 

 they proved nothing. They were only suggestive, and the con- 

 clusion was that frost at least assists, even tliough dextrine and 

 ferment get the credit. A hard frost in the fall, by checking the 

 process of maturation, if it does not turn back the starch and cel- 

 lulose to dextrine and sugar, at least affects them in such a way 

 that less work has to be done in the preparation for germination in 

 the spring, so that the young plant comes earlier into activity, and 

 with a richer or denser sap. A statement in one of the magazines, 

 that frost killed some plants sooner than others, because of the 

 difference in their density, due to the difference in the size of their 



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