ON THE ROOTS OF TREES, 34 I 



in every direction, and a very little depth for such large and 

 high trees. The division of the root, indeed, takes place in all 

 the firs much higher in the stem than in other trees., None of 

 the firs have any reservoir of alburnum, as is found in the se- 

 cond part of the root of the oak, &c. or I have not yet been 

 able to discover it, from their not having a tap-root to guide me 

 in the search ; but I shall look more carefully. I have, how- Dissected 

 ever, dissected more than four dozen fir trees of all ages and ^^"7 "• 

 sizes, growing naturally, and transplanted, not only in seeking 

 that, but the tap-root also, but in neither have I succeeded. 

 The tap-root in other trees, though, from being removed, it 

 has branched and lost its shape, yet is always known ; and so 

 it would be in the firs, I doubt not, if they had any. But in 

 all I have seen, there is not the smallest appearance of one, and 

 if one of the side roots has been by accident turned down, its 

 increased shape, on one side, shows that it was originally a side 

 root forced into another situation — yet the exact Evelin also Is 

 mistaken. There is some variation in the bark and rind — they Bark and rind 



are not exactly like those of the stem. At first I thought they "°^ ^"^"^ *^^ 



° ■' same, 



were not composed of leaves, as the coverings of the trunk of 



all firs are (see my letter on the subject in your Journal, 

 33 ;) but that was undoubtedly my mistake — they are formed 

 of leaves, but thinner than the stem. The greatest part of the 

 bark division is engrossed by that curious matter which sepa- 

 rates the inner bark from the alburnum, and even in old roots 

 is discovered to be of the most silvery whiteness ; and its situa- 

 tion has so changed its very nature, that, instead of a thin divi- 

 sion of h^rd rough wood, it appears like the most beautiful 

 soft white leather. Surely its changing thus must show the 

 excessive power of the juices of the firs in softening and tan- 

 ning leather, and its vast superiority over the oak bark, or that Superiority ©f 

 of any other tree now made use of for the purpose — for though ^j^^ J„"'cs3 of 

 the oak has a very thin layer of this same matter to keep the 

 debilitating juices from the wood, it is not softened and emo- 

 licated by its liquid, nor has it attained any thing like the sup- 

 pleness or delicacy of that which encloses the fir, (as all may 

 see that examine it) though they are both woods originally of 

 nearly the same degree of roughness and hardness. I most wish that 

 sincerely wish that Sir H. Davy, or his brother, would turn their sorn^ chemist 

 attention to this subject — it is very unlikely that nature would 



give 



