20 Prof. Bailey on the Crystals found in Plants. 



The detection of such vast quantities of crystals in every 

 species of hickory, and the indications of similar phenomena in 

 other trees, presented by their remains in ashes, led me to exam- 

 ine many other trees. I soon found that the bark of every spe- 

 cies of oak, birch, chestnut, poplar, elm, locust, and all the com- 

 mon fruit trees, as the apple, pear, cherry, plum, &c., besides a 

 vast number of others, were literally crowded with crystals. 



The thin layers of the liber of the poplar, locust, chestnut, Sic. 

 when moistened and examined by the microscope, presented a 

 most beautiful mosaic work of crystals. Each of the cells of the 

 liber shewed either single or twin crystals, disposed as seen in 

 figure 5, which was drawn from the liber of Populus grandi- 

 dentata, but which will serve to show the form and arrangement 

 of the crystals in all the trees just mentioned, as well as in 

 many others.* 



Even when it is difficult to see the crystals in situ, owing to the 

 presence of globules of starch and chlorophylle, or to the density 

 of the tissues, they may yet, in general, be found by scraping the 

 wood or bark into water, in a watch glass. When the woody 

 particles are picked out, the residue will generally show abun- 

 dance of crystalline matter. By this method crystals may be 

 obtained in an isolated state, even from such dense woods as ma- 

 hogany, heart of oak and lignum-vitas, and even when this pro- 

 cess does not give good results, the presence of the crystals in 

 great quantity may be demonstrated by placing a portion of the 

 ashes in Canada balsam. They may be readily found in the 

 powdery matter of worm-eaten wood ; in saw-dust also ; and 

 abundantly in the finer portions of the ground dye-stuffs of com- 

 merce, such as logwood, fustic, quercitron, Brazil wood, sandal 

 wood, camwood, &c. 



The examination of leaves also gave very beautiful results. 

 By slowly burning the leaf until the ashes became perfectly 

 white, the form of the leaf was usually retained, and when en- 

 cased with Canada balsam showed beautifully the saline skeleton 

 of the leaf. In the full grown leaves of most trees, it was found 

 by this method that rows of crystals accompany every ramifica- 

 tion of the vascular bundles, so that even the minutest vein of 

 the leaf is represented in the ashes by its row of crystalline par- 



* The appearance by polarized light is very beautiful, presenting an elegant 

 mosaic work of rubies and emeralds. 



