not deposit at all under similar circumstances. The
lowest temperature observed was -13.3 deg. C. (8 deg. F.), the
thermometer bulb being immersed in the oil.

A few qualitative tests, viz., the action of sulphuric acid, nitric
acid (sp. gr. 1.42), and digestion, with more dilute nitric acid (1.2
sp. gr.) and a globule of mercury, were first tried.

When one drop of sulphuric acid is added to eight or ten drops of tea
oil on a white plate, the change of color observed is more like that
when almond oil is similarly treated than with any other oil, olive
oil coming next in order of similarity.

When a few drops of tea oil are boiled with thirty drops or so of
nitric acid in a small tube, the layer of oily matter, when the brisk
action has moderated, is of a light yellow color, similar in tint to
that produced from almond and olive oil under similar circumstances.
When the oil is digested with an equal volume of nitric acid (1.2 sp.
gr.), and a globule of mercury added, the whole becomes converted
into a mass of elaidin in about two hours, of the same tint as that
produced from almond oil when similarly treated.

These tests point to the fact that the oil may be considered as
resembling almond or olive oil in composition, a conclusion which is
borne out by the subsequent experiments.

(3.) _Free Acidity of Oil._--The oil was found to contain free acid
in small quantity, which was estimated by agitating a weighed quantity
with alcohol, in which the free acid dissolves while the neutral fat
does not, and titrating the alcoholic liquid with decinormal alkali,
using solution of phenol-phthalein as an indicator.

It was thus found that 100 grammes of the oil require 0.34 gramme of
caustic potash to neutralize the free acid. Mr. W. H. Deering (_Journ.
Soc. of Chem. Industry_, Nov., 1884) states that in seven samples of
olive oil examined by him, the minimum number for acidity was 0.86 per
cent., and the maximum 1.64 per cent., the mean being 1.28 per cent.
Tea oil compares favorably with olive oil, therefore, in respect of
acidity, a quality of which note has to be taken when considering the
employment of oil as a lubricating agent.

(4.) _Saponification of the Oil._--Considerable light is thrown on the
composition of a fixed oil by ascertaining how much alkali is required
to saponify it. In order to estimate this, a known excess of alcoholic
solution of potash is added to a weighed quantity of the oil,
contained in a st