The usual chemical constants were determined, namely, the acid number,
ester number, saponification number, and acetylization number.
The acid number, denoting the amount of free acids contained in the
oil and expressed in milligrams of potassium hydroxid, was determined
by simple neutralization of the oil with standard potassium hydrate
volumetric solution.
The ester number, denoting the amount of esters (combination of
alcohols and acids) in the oil and expressed in milligrams of potassium
hydroxid, was determined by saponification of the ester compounds with
alcoholic potassium hydrate.
The acetylization number, or the ester number determined after
acetylization of the oil with acetic anhydrid, signifies the total
amount of alcohol or alcohols in the oil.
The constants of the oil were determined with the following results:
Acid number, 2.5, calculated as acetic acid, indicates 0.26 per cent
acetic acid.
Ester number, 25, calculated as bornyl acetate, indicates 8.7 per
cent bornyl acetate, which is equivalent to 6.8 per cent of free
borneol.
Saponification number, 27.5.
Acetylization number, 139, corresponds to 42.67 per cent of total
borneol in the oil, or, deducting the 6.8 per cent of free borneol as
the ester, to 38 per cent of free borneol.
Assuming that the stearoptene obtained was borneol, a determination
of the constants of the stearopteneless oil was made. The acid number
remained practically the same, being 2.3; the ester number differed
only very slightly, being 24.7; but the acetylization value obtained
was only 132, which corresponded to but 40 per cent of total borneol.
This is in strict conformity with the assumption, which seemed to be
sufficiently proved, that the stearoptene separated from the oil by
freezing was borneol. The stearopteneless oil was nearly 3 per cent
poorer in borneol than the original oil, as shown above. It is to
be remembered that 3 per cent of crystalline borneol was removed by
freezing the original oil, hence the lowering of the borneol content of
the stearopteneless oil.