ae ae ee PY ee oe Pin BAT nat SRT ae 
: 
Sieh ili eta h lhl seagt cahemaaminas annie? iia a A ta ati 
ae 
Panes 
tion before the completed structure of the plant was obtained. _ 
CONSTITUENTS OF THE SAP OF THE SILKY OAK. 201 
That the magnesia is not present as a sulphate or as a chloride, 
because no magnesia was found in the soluble portion of the 
ignited residue, nor sulphuric acid in the insoluble portion ; the 
small amount of sulphuric acid was found in the soluble portion 
and was probably present in connection with the alkalis, but of 
this I have no evidence outside the ready solubility of the sulphate, 
as only small quantities of cold distilled water, repeatedly applied, 
were used to extract the soluble portion from the ignited residue, 
no heat being applied. 
It appears from numerous investigations and analyses of the 
ash of many plants, that the elements of this class most necessary 
to the growth of the tree, are sulphur, phosphorus, calcium, mag- 
nesium, potassium, iron, and possibly chlorine. All of these were 
found existing in this sap, while in addition we find sodium, and 
nitrogen, the former in fair quantity, the latter only in traces. 
No evidence was obtained as to the form in which the nitrogen was 
present, or with what constituent, but nothing was precipitated 
on boiling the original sap. The aluminium was found to be 
present in only very minute quantities, thus again confirming the 
inert character of this abundant element. It is thus the more 
remarkable that such a large deposit of aluminium succinate 
should have accumulated in the timber as described in the paper 
already referred to. ; 
The general statement that calcium is present in the form of 
sulphate, phosphate, or carbonate, appears to be of too broad a 
character, and although no doubt correct in some instances, yet, 
it is not so in this sap. The chemical alteration and molecular 
arrangement of these inorganic salts within the cells of the grow- 
ing tree, is no doubt different under altered conditions, and not 
always the same as theoretically supposed from information — 
obtained by artificial cultures, In the estimation of the ash after 
“Incineration, we only arrive at the extreme stage of alteration, 
but we do not know all the changes that have taken place during 
the Process, or what has been the order of the molecular altera- 
