112 



VIEWS OF THE MICROSCOPIC WORLD. 



The size of these crystals is very small, not being greater in some trees, as the 

 Fig- 178 Fig 179 locust, willow, (fee., than the 



twelve hundred and fiftieth of an 

 inch in length ; but their number 

 is so great that within the com- 

 pass of a square inch of bark, 

 not thicker than a sheet of writ- 

 ing paper, more than a million of 

 these beautiful gems are collected together. And when we reflect, says Prof. B., 

 " upon the number of such layers contained in the thickness of the bark, and 

 the number of square inches given by the surface of a large tree, including all 

 its branches, and then consider, that in addition to all this, the amount of crys- 

 tals contained in the leaves, wood and roots is to be taken into account, we find 

 that the number of crystals in a single tree is enormous beyond all con- 

 ception. Yet the greater number of trees in the forests, not only in this but 

 in all countries, are as full of these bodies as the specimens exhibited in figure 

 171." When the crystals found in wood are subjected to chemical tests they 

 are generally found to be composed of oxalate of lime. Between the figures 

 178 and 179 a small scale of measurement is seen, which is magnified to the 

 same extent as the crystals above described. The true length of the scale in 

 the cut is one-five hundredth of an inch, and each division is equal in extent to 

 one-twenty five hundredth of an inch ; by comparing these divisions of the scale 

 with the size of the crystals, their exceeding minuteness is at once recognised. 

 In figure 180 is exhibited a collection of crystals obtained in the manner de- 

 scribed by Prof. Bailey. Fix- 

 ed in the indurated balsam 

 they appear, in vast numbers, 

 under the microscope, of a 

 brown color, and bearing a re- 

 semblance in their shape to 

 kernels of rice. A single crys- 



Fig. 180. 



of an inch. 



The delicate crystalline tra- 

 cery existing in the burnt ashes 

 of a maple leaf, is beautifully 

 displayed in figure 181. The 

 leaf from which the drawing 

 was taken was prepared in the 

 way above stated, when upon 

 placing a portion of the ashes 



beneath the microscope, fine lines of brilliant crystals were beheld, as exhibited in 

 the figure, following all the minute ramifications of the leaf. Some of the lines 



