342 <^N THE ROOTS OF TREES. 



give such a proof of this, if it was not thoroughly worthy the 

 strictest attention. I have not yet described all the motion 

 *" that belongs to wood in the roots : as this is equally found in 

 firs as in all forest trees, I have retained it as the last explana- 

 tion. It is inconceivable what alteration two inches, or even one, 

 will sometimes produce in a piece of root. I have seen the 

 pith change its place two or three times in as many inches. I 

 have now a piece by me where all the ovals are within one 

 another, and of sixty in number, change in less than three 

 inches in length to three regular circles, each circle bearing 

 interlacing figures of fifty-nine each. Conceive what must be 

 the motion of wood, that would, in so short a space, produce 

 such a revolution of ybrm and Jtg/«t' / it was only in tnicing 

 each sap-vessel in length, that I could persuade mystlf of the 

 reality j the stems of trees are infinitely more quiet in this 

 respect, and generally retain the pith at the same side, unless 

 some cause, such as rot, or any injury happening to force a 

 change. But it is very different in the root ; that perpetual 

 motion appenrs necessary to it is certain, and I doubt not con- 

 tributes to its health ; and, by seeking further, we may be the 

 means of developing many of the disorders of wood. How 

 often we find, that laying the earth lighter on the roots gives 

 Knowledge of fresh vigour to the tree: this knowledge of its motion will 

 dI^ '""^"^'^ ° open a source of refreshment of great consequence, I should 

 hope, to their general health. In short, the more we are ac- 

 quainted with their inward structure, the more we shall be 

 able to administer to their diseases. In this situation it may 

 be compared to the advice given in a surgical case by a person 

 a proficient in anatomy, and one wholly ignorant of it — he who 

 is best acquainted Vv'ith the formation is more likely to hit on 

 of use in gar- the real disorder. May we not, therefore, hope, that, by gain- 

 dening. j^g a thorough knowledge of the interior of plants, it may, in 



' time, lead us to an acquaintance with their diseases, and give 

 us some notion how to remedy them. I am collecting a set 

 of specimens to show the different disorders in trees and their 

 causes ; and when I am advanced enough, shall lay them before 

 the public. 



I am, Sir, 



Your obliged Servant, 



AGNES IBBETSON. 



The 



