_Tobacco._
QUALITIES. _Odour_, strong, narcotic, and fœtid; _Taste_, bitter, and
extremely acrid; _Colour_, yellowish green, (its brown appearance is
artificial, being produced by the action of _sulphate of iron_.)
CHEMICAL COMPOSITION. Mucilage, albumen, gluten, extractive, a bitter
principle, _an essential oil_, nitrate of potass, which occasions its
deflagration, muriate of potass, and a peculiar proximate principle upon
which the properties of the plant are supposed to depend, and which has
therefore been named _Nicotin_.[658] Vauquelin considers it as
approaching the volatile oils in its properties; it is colourless, has
an acrid taste, and the peculiar smell of tobacco, and occasions violent
sneezing; with alcohol and water, it produces colourless solutions, from
which it is thrown down by tincture of galls. SOLUBILITY. Tobacco yields
its active matter both to water and spirit, but more perfectly to the
latter; long coction weakens its powers. An oil of tobacco of a most
powerful nature, may be obtained by distilling the leaves and separating
it from the water, on the top of which it will be found to float.[659]
MED. USES. Tobacco is endued with energetic poisonous properties,
producing generally a universal tremor which is rarely the result of
other poisons; the experiments of M. Orfila moreover demonstrate, that
the action of Tobacco is much more energetic when the soluble portion is
injected into the anus, than when it is applied to the cellular texture,
and for a still stronger reason, than when introduced into the stomach.
Mr. Brodie, from the result of a well devised experiment, has deduced
the conclusion that the infusion of Tobacco acts upon the heart,
occasioning syncope, through the medium of the nervous system. USES. As
a powerful sedative, it is sometimes valuable in medical practice; the
leaves, when applied in the form of a cataplasm to the pit of the
stomach, produce an emetic operation; (_Form. 67._) In cases of
obstinate constipation, depending upon violent spasmodic constriction,
or in _ileus_, or _incarcerated hernia_, clysters of the smoke of
Tobacco, or of an infusion made according to the London College, produce
almost immediate relief, (_Form. 26._); the practice is not unfrequently
attended with severe vomiting, extreme debility, and cold sweats,
circumstances which render its administration highly dangerous in cases
wherein the patient has been already exhausted by previous suffering. I
remember witnessing a lamentable instance of this truth some years ago;
a medical practitioner, after repeated trials to reduce a strangulated
hernia, injected an infusion of Tobacco, and shortly afterwards sent the
patient in a carriage to the Westminster Hospital, for the purpose of
undergoing the operation; but the unfortunate man arrived only a few
minutes before he expired. Clysters of Tobacco were some years ago
recommended in America, for the purpose of forwarding difficult
parturition, by inducing relaxation and consequent dilatation of the _os
uteri_, but the alarming symptoms which followed the single case in
which Tobacco was thus employed, ought, says _Dr. Merriman_, to prevent
a repetition of the experiment.[660] It was also formerly proposed to
inject infusions of Tobacco, for the purpose of recovering persons in a
state of _asphyxia_ from drowning; it is difficult to explain how such
an idea could have entered into the mind of the rational physiologist.
Smoking or chewing Tobacco has been also advised in cases of spasmodic
asthma, and as a general sedative to relieve suffering; in the process
of _smoking_, the oil is separated, and being rendered empyreumatic by
heat, it is thus applied to the fauces in its most active state. As a
diuretic it was successfully exhibited by Dr. Fowler, but as its
operation is uncertain and violent, and appears to be very analogous to
that of Digitalis, which is far more safe and manageable, it has been
very judiciously discarded from practice. The external application of
Tobacco in the form of cataplasm or infusion, has been applied to
several species of cutaneous disease, but even in this state it is
liable to exert its virulent effects. A woman applied to the heads of
three children afflicted with _tinea capitis_, a liniment consisting of
powdered tobacco and butter, soon after which they experienced vertigo,
violent vomiting, and fainting. (_Ephemerides des Curieux de la Nature_,
Dec. ii. An: i. p. 46.) A case has just occurred in this country of a
child whose death was occasioned by her having swallowed a portion of
half-smoked tobacco, which was taken from the pipe of her father, and in
which there no doubt existed a quantity of essential oil, which had been
separated by the act of smoking. It is a curious fact, that the juice of
the green leaves instantly cures the stinging of nettles.
ADULTERATIONS. When it exhales a fetid odour, we may infer that it has
been badly prepared, and not deprived of all its mucus; when pungent,
the presence of some deleterious drug is indicated: Cascarilla is very
usually added to impart a peculiar flavour; Nitre is also employed for
the sake of making it kindle more rapidly, and to impress a lively
sensation on the tongue; its vapour is of course very injurious to the
lungs: its presence may be detected by treating a suspected sample with
hot water, and after filtering the solution through charcoal, setting it
aside in order that it may yield its crystals by evaporation. Traces of
_Lead_, _Copper_, or _Antimony_, may be discovered by boiling the
Tobacco in strong vinegar, and, after filtering it as before, by
assaying it with appropriate tests. _Black Hellebore_, _Alum_, _Sugar_,
and _Corrosive sublimate_ are amongst the more usual sophistications.
_Dried Dock_ leaves are also sometimes substituted. OFFICINAL PREP:
_Infus: Tabacci_. L. _Vinum Nicotian: Tabac:_ E.
SNUFF. This well known errhine is prepared from the dried leaves of
Tobacco; in its manufacture however, numerous additions are made which
are kept secret. _Salt_ is added for the purpose of increasing its
weight; _Urine_, Muriate of ammonia, and powdered Glass, to heighten its
acrimony. The varied flavour of different _Snuffs_ is owing to the leaf
being in greater or less perfection; or to its having undergone some
degree of fermentation; thus, for instance, the _Macouba Snuff_ of
Martinique is principally indebted for its acknowledged superiority to
the fermentation which the Tobacco undergoes, from being moistened with
the best cane juice; other kinds are excited into fermentation by
moistening them with melasses and water.
Snuff possesses all the powers of Tobacco; the celebrated Santeuil
experienced vomiting and horrible pains, amidst which he expired, in
consequence of having drank a glass of wine, into which had been put
some Spanish snuff.[661]