100 PLAINT AND PXEASANT TALK 



them. The point of death is usually near the surface of the 

 ground, where the under-ground bark and upper bark 

 come together. Whole orchards are destroyed in this 

 way ; and, if examined, the bark may be found sprung off 

 from the wood. This may occur at any time during the 

 winter. 



We are in doubt whether the winter-stored sap exists in 

 a state to be affected by the expansion of the freezing fluids 

 of the tree. If the expansion of congelation did produce 

 the effect, it should have been more general, for there are 

 fluids hi every part of the trunk all congeal or expand 

 and the bursting of the trunk in one place would not 

 relieve the contiguous portions. We should expect, if this 

 were the cause, that the tree would explode, rather than 

 split. Capt. Bach, when wintering near Great Slave Lake, 

 about 63 north latitude, experienced a cold of 70 below 

 zero. Nor could any fire raise it in the house more than 

 12 above zero. Mathematical instrument cases, and boxes 

 of seasoned fir, split in pieces by the cold. Could it have 

 been the sap in seasoned fir wood which split them by its 

 expansion in congealing ? 



We quote a paragraph from Loudon " The history of 

 frosts furnishes very extraordinary facts. The trees are 

 often scorched and burnt up, as with the most excessive 

 heat, in consequence of the separation of the water from 

 the air, which is therefore very drying. In the great frost 

 in 1683, the trunks of oak, ash, walnut, and other trees, 

 were miserably split and cleft, so that they might be seen 

 through, and the cracks often attended with dreadful noises 

 like the explosion of fire-arms." 



We don't exactly know whether to take the first part as 

 London's explanation of the facts in the second. 



There can be no doubt that the nature of the summer's 

 growth, very much determines the power of a tree to resist 

 the severity of winter. When there is but an imperfect 

 ripening in a cold and backward season, the tissues formed 



