62 TEXTURE OF VEGETABLE:-. 



pie in the bark of the Oak, whose layers in a living state 

 are closely connected with each other by the cellular 

 texture, but in consequence of long exposure this tex- 

 fure is destroyed and the separate layers only remain. 

 But with this substance, the astringency of the Oak is 

 gone. And if the bark of the Cinnamon be for a while 

 subjected to the action of boiling water ; the woody 

 fibres of the net-work remain uninjured but it loses its 

 exquisite flavour which probably resides in the inter 

 vening pulp. 



SECTION 4. 

 WOOD. 



The texture of the Wood which constitutes Uuj 

 great mass of trees and shrubs, was investigated with 

 peculiar care by Duhamel, and the same subject has 

 been more recently pursued by Mirbel and Knight, 

 with their usual ingenuity and success. 



An old stem of the Currant, when transversely di- 

 vided, exhibits a series of concentric layers intersected 

 by plates which diverge from the pith to the bark, 

 like the ray* of a circle.* A transverse section of the 

 Oak presents a similar arrangement, but here the cir- 

 cular iayers are considerably thicker and the divergent 

 plates far more conspicuous than in the preceding ex- 

 ample. And if we would pursue the examination still 

 farther, the Ash, the Elm, and the Lilac, will serve to 

 !-hew that the arrangement so obvious in the Oak, pre- 

 vails also in other woody stems* The central layers 

 are usually most durable and complete, for those of the 

 circumference being still under the control of a living 

 principle, retain a portion of their peculiar juices,' 



* Pigs. 7 and 8. 



