Medical Jurisprudence And Toxicology

686

MEDICAL JURISPRUDENCE

Chemical Analysis. — The resin is contained in the acid ether extract of
the suspected organic material obtained by the Stas-Otto process, arid is
recognized by the following tests : —

1. Beam's Alkaline Test.— The extract is treated with a small quantity
of animal charcoal to remove the colouring matter, especially the chlorophyll
of the crude drug, and is filtered before evaporating to dryness in a small
porcelain capsule. A few drops of a 5 to 10 per cent alcoholic solution of
potash are added, when a violet colour gradually develops, which may be
hastened by warming.

This test may also be performed by dissolving the residue in a few drops
of petroleum ether and soaking a piece of filter paper in this solution. The
paper is then evaporated spontaneously and moistened with a drop of the
alcoholic potash, when a violet colour appears at once.

2. Beam's Acid Test. — A few drops of absolute alcohol saturated with
dry hydrochloric acid gas are added to the residue dissolved in a few drops
of petroleum ether, when a red colour is produced,

The preparations of cannabis indica, such as the tincture and extract,
often fail to respond to this test.

3. Bouquet's Test. — If a few drops of a freshly prepared mixture of
concentrated sulphuric acid (2 vols.) and absolute alcohol (3 vols.) are added
to the extracted residue dissolved in a few drops of acetone after it is de-
colourized by animal charcoal, if necessary, a dark colour appears, which
becomes cherry red in about an hour. The addition of a few drops of water
renders the solution colourless but opalescent.

4. Aldehyde Test. — A few drops of the reagent made by dissolving 1 g,
of para-dimethylamino-benzaldehyde in 100 cc. of alcohol and adding 20 drops
of concentrated sulphuric acid are added to the residue in a porcelain, basin,
The mixture is then evaporated to dryness, when a bright violet colour
appears.

Bhang and other forms of cannabis sativa used by addicts may be identi-
fied under the microscope by the presence of retort-shaped, short, unicellular,
cystolithic hairs and long, thin tapering hairs, having no cystoliths. The
following method is recommended for carrying out the microscopic exami-
nation : —

The suspected particles are placed on a slide, and a drop of dilute
caustic soda solution is added. They are then covered with a cover-slip and
examined first under the 1/3" and then under the 1/6" objective, when the
morphological features of the hairs will be
observed distinctly. The ganja hairs appear
smooth, and the hairs found in charas are
warty,

For the microscopic examination of majun,
sugar, butter and other substances should first
be removed by washing successively with
petroleum ether, alcohol and hot water. The
residue is then treated with dilute alkali and
examined.

In the case of ganja or charas mixed with
tobacco or any other dry substance the sus-
pected particles should be freed from foreign
matter, rubbed with a little water in a mortar
and mixed with some chloral hydrate solution
The mixture is transferred to a test tube and -

boiled for a few seconds, wheix the finer parti- r*C™<^

Fig. 187,— Cannabis sativa Hairs :
°" <an]a Hairs' b* char^ Hairs.