FRUIT AND FOREST TREES. 
309 
carries outwards certain elements which are of greater importance than others. I allude 
here particularly to the phosphates, which, it is well known, are of primary importance 
in the fruit and seeds. The analyses have been conducted in part with reference to this 
supposed law of outward movement. The plan adopted, and which has been generally 
followed, was to divide the tree into the following parts : 1, the inside wood, or heart 
wood ; 2, the outside wood ; 3, the bark ; 4, the wood of the twigs; 5, the bark of the 
twigs ; 6, the leaves ; 7, the seed, and the fruit with its envelopes. This plan of proceeding 
appeared to exhaust the subject, unless indeed we extend it so far as to inquire what changes 
take place in the amount of the elements in the different seasons. A few analyses have 
been made under this inquiry. The subject is of sufficient importance to merit a careful 
investigation. 
The proper preparation of the ash is an operation that has been attended with some 
trouble. It is very liable to become caustic, or sub-caustic, and hence it happens that 
sufficient carbonic acid is never obtained to saturate the bases. This is not a matter of so 
much consequence as might at first appear : carbonic acid is not regarded as a constituent 
of the wood, but as a secondary product formed from the organic acid by ignition ; and 
the object in determining the amount of carbonic acid, is to test the accuracy of the ana¬ 
lysis. The ash should be prepared at as low a temperature as possible, which shall at the 
same time secure a perfect combustion of the organic matter. 
STATEMENT OF SOME RESULTS OF THE FOLLOWING ANALYSES. 
I. It appears as a general result of the following analyses, that solubility controls in part 
the distribution of the inorganic matter of vegetables. Water never accumulates in the 
interior, or in the heart wood of a tree, but is carried upwards and outwards, and hence 
is found in a greater proportion in the leaves and in the outside wood. Being itself the 
great medium through which the solid matters are conveyed and distributed throughout 
the organs of vegetables, it is agreeable to what we might deduce a priori in regard to the 
distribution of the several proportional amounts of the inorganic matter. Moving as it is 
found to do, in a larger quantity to the periphery of the head and trunk, it must necessarily 
carry to the periphery a greater amount of solids than to the interior. 
II. The distribution is not wholly controlled by the present movements of the water or 
sap which enters into the circulation of a tree. Some of the materials which form the 
wood of the interior is also absorbed and carried outwards to the periphery, or to the trunk. 
This statement is borne out by the results which have been so often obtained. The amount 
of ash of green and living wood is almost uniformly greater in the outside wood than in 
the heart wood. These two kinds of wood being weighed immediately after the tree is cut 
down, and equal portions of each taken, notwithstanding the water of the outside usually 
surpasses that of the inside, its ash exceeds that of the inside. 
III. The bark of trees, as well as the outside covering of seeds, differs essentially in 
