The Comparative Chemistry of our Forest Trees. 
By P. Q. Krercan, LL.D. 
By the chemistry of trees is meant not the special detection and 
demonstration of the chemical forces which exert energy within the 
living arboreal organism, but rather the detection and assignment of 
such separable and distinctive organic and inorganic bodies as are 
incidental to the vital processes thereof, whether these bodies furnish 
the stroma of the actual life, or are merely bye- or waste- products 
of the spent and exhausted activities. The tree, indeed, may be 
regarded as the outward and visible sign of an inward and wholly 
invisible force. The capital force is the mysterious one called “ vital ;” 
but chemical forces and their visible or detectable products, which here 
alone concern us, are set agoing thereby, and are manifested as a heritage 
or inevitable consequence. Nevertheless, it is absolutely certain that 
some of the most brilliant, beautiful, and distinctive constituents of the 
tree—of its stem, leaf, and flower—are not the results of any chemical 
processes known to us, and cannot possibly be artificially reproduced by 
the most capable and dexterous application of the latest and most 
approved synthetic methods and expedients. 
The arborescent forms of the forest flora of the British Islands are 
not very numerous, but (native and denizen species included) they are 
sufficiently varied to render an account of their chemical constituents 
exceedingly interesting and instructive. If, for instance, we desire to 
study the chemical characteristics of the Gymnosperms, we can forth- 
with fasten on that stately and sombre-foliaged tenant of our upland 
wastes and craggy mounds known as the Scotch Fir (Pinus sylvestris). 
Perhaps we have been accustomed to consider the leaf as the most 
vigorously active of the vegetable organs, but here we see that a mighty 
portion of the energy is delegated to the woody tissues. For what is 
the meaning of the resinous matter which is so characteristic a con- 
stituent of the Coniferae, and the origin of which has been the theme 
of such acute and prolonged controversy? Some specially active 
mother-cells containing an opaque plasma, and situated in the external 
heart-wood, divide and divide again with great energy, separating from 
the adjoining tissue, and forming four to eight or more daughter cells 
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