_Herba Nicotianæ_; _Tobacco_; F. _Tabac_; G. _Tabakblätter_.
=Botanical Origin=—_Nicotiana Tabacum_ L.—The common Tobacco plant is
a native of the New World, though not now known in a wild state. Its
cultivation is carried on in most temperate and subtropical countries.
=History=—It is stated by C. Ph. von Martius[1707] that the practice
of smoking tobacco has been widely diffused from time immemorial among
the natives of South America, as well as among the inhabitants of the
valley of the Mississippi as far north as the plant can be cultivated.
The Spaniards became acquainted with tobacco when they landed in Cuba
in 1492, and on their return introduced it into Europe for the sake
of its medicinal properties. The custom of inhaling the smoke of the
herb was learnt from the Indians, and by the end of the 16th century
had become generally known throughout Spain and Portugal, whence it
passed into the rest of Europe, and into Turkey, Egypt, and India,
notwithstanding that it was opposed by the severest enactments both of
Christian and Mahommedan governments. It is commonly believed that the
practice of smoking tobacco was much promoted in England, as well as in
the north of Europe generally, by the example of Sir Walter Raleigh and
his companions.
Tobacco was introduced into China, probably by way of Japan or Manila,
during the 16th or 17th century, but its use was prohibited by the
emperors both of the Ming and Tsing dynasties. It is now cultivated in
most of the provinces, and is universally employed.[1708]
The first tolerably exact description of the tobacco plant is that
given by Gonzalo Fernandez de Oviedo y Valdés, governor of St. Domingo,
in his _Historia general de las Indias_,[1709] printed at Seville in
1535. In this work, the plant is said to be smoked through a branched
tube of the shape of the letter =Y=, which the natives call _Tabaco_.
It was not until the middle of the 16th century that growing tobacco
was seen in Europe,—first at Lisbon, whence the French ambassador, Jean
Nicot, sent seeds to France in 1560 as those of a valuable medicinal
plant, which was even then diffused throughout Portugal.[1710]
Monardes,[1711] writing in 1571, speaks of tobacco as brought to Spain
a few years previously, and valued for its beauty and for its medicinal
virtues. Of the latter he gives a long account, noticing also the
methods of smoking and chewing the herb prevalent among the Indians. He
also supplies a small woodcut representing the plant, which he states
to have white flowers, red in the centre.
[1707] _Beiträge zur Ethnographie und Sprachenkunde Americas, zumal
Brasiliens_, i. (1867) 719.
[1708] Mayers in _Hong Kong Notes and Queries_, May, 1867; F. P. Smith,
_Mat. Med. and Nat. Hist. of China_, 1871. 219.
[1709] Lib. v. c. 2.
[1710] Nicot, _Thrésor de la langue Françoyse_, Paris, 1606. 429.
[1711] _Segunda parte del libro de las cosas que se traen de nuestras
Indias occidentales, que sirven al uso de medicina._ Do se trata del
Tabaco ..., Sevilla, 1571, 3.
Jacques Gohory,[1712] who cultivated the plant in Paris at least as
early as 1572, describes its flowers as shaded with red, and enumerates
various medicinal preparations made from it.
In the _Maison Rustique_ of Charles Estienne, edition of 1583, the
author gives a “_Discours sur la Nicotiane ou Petum mascle_,” in which
he claims for the plant the first place among medicinal herbs, on
account of its singular and almost divine virtues.
The cultivation of tobacco in England, except on a very small scale in
a physic garden, has been prohibited by law[1713] since 1660.
=Description=—Amongst the various species of _Nicotiana_ cultivated
for the manufacturing of smoking tobacco and snuff, _N. Tabacum_ is
by far the most frequent, and is almost the only one named in the
pharmacopœias as medicinal. Its simple stem, bearing at the summit a
panicle of tubular pink flowers, and growing to the height of a man,
has oblong, lanceolate simple leaves, with the margin entire. The lower
leaves, more broadly lanceolate, and about 2 feet long by 6 inches
wide, are shortly stalked. The stem-leaves are semi-amplexicaul, and
decurrent at the base. Cultivation sometimes produces cordate-ovate
forms of leaf, or a margin more or less uneven, or nearly revolute.
All the herbaceous parts of the plant are clothed with long soft hairs,
made up of broad, ribbon-like, striated cells, the points of which
exude a glutinous liquid. Small sessile glands are situated here and
there on the surface of the leaf.[1714] The lateral veins proceed from
the thick midrib in straight lines, at angles of 40° to 75°, gently
curving upwards only near the edge. In drying, the leaves become
brittle and as thin as paper, and always acquire a brown colour. Even
by the most careful treatment of a single leaf, it is not possible to
preserve the green hue.
The smell of the fresh plant is narcotic; its taste bitter and
nauseous. The characteristic odour of dried tobacco is developed during
the process of curing.
=Chemical Composition=—The active principle of tobacco, first isolated
in 1828 by Posselt and Reimann, is a volatile, highly poisonous
alkaloid termed _Nicotine_, C₁₀H₁₄N₂. It is easily extracted from
tobacco by means of alcohol or water, as a malate, from which the
alkaloid can be separated by shaking it with caustic lye and ether. The
ether is then expelled by warming the liquid, which finally has to be
mixed with slaked lime and distilled in a stream of hydrogen, when the
nicotine begins to come over at about 200° C.
[1712] _Instruction sur l’herbe Petum ditte en France l’herbe de la
Royne ou Médicée_ ... Paris, 1572.
[1713] 12 Car. II. c. 34; 15 Car. II. c. 7.—For further information
on the history of tobacco, see Tiedemann, _Geschichte des Tabaks_,
Frankfurt, 1854.—We have not consulted Fairholt, _Tobacco, its
History_, Lond. 1859.
[1714] Microscopic structure of tobacco leaves. See Pocklington,
_Pharm. Journal_, v. (1874) 301.
Nicotine is a colourless oily liquid, of sp. gr. 1·027 at 15° C.,
deviating the plane of polarization to the left; it boils at 247° and
does not concrete even at -10° C. It has a strongly alkaline reaction,
an unpleasant odour, and a burning taste. It quickly assumes a brown
colour on exposure to air and light; and appears even to undergo an
alteration by repeated distillation in an atmosphere deprived of
oxygen. Nicotine dissolves in water, but separates on addition of
caustic potash; it occurs in the dried leaves to the extent of about 6
per cent., but is subject to great variation. The seeds of tobacco are
stated by Kosutany[1715] as grown in Hungary to contain from 0·28 to
0·67 per cent. of the alkaloid.
It has not been met with in tobacco-smoke by Vohl and Eulenberg
(1871), though other chemists assert its occurrence. The vapours
were found by the former to contain numerous basic substances of the
picolinic series, and ceded to caustic potash, hydrocyanic acid,[1716]
sulphuretted hydrogen, several volatile fatty acids, phenol and
creasote. There was further observed in the imperfect combustion
of tobacco the formation of laminæ fusible at 94° C., and having a
composition C₁₉H₁₈. Oxide of carbon is also largely met with.
Tobacco leaves, whether fresh or dried, yield when distilled with water
a turbid distillate in which, as observed by Hermbstädt in 1823, there
are formed, after some days, crystals of _Nicotianin_ or _Tobacco
Camphor_. According to J. A. Barral, nicotianin contains 7·12 per cent.
of nitrogen (?). By submitting 4 kilogrammes of good tobacco of the
previous year to distillation with much water, we obtained nicotianin,
floating on the surface of the distillate, in the form of minute
acicular crystals, which we found to be devoid of action on polarized
light. The crystals have no peculiar taste, at least in the small
quantity we tried; they have a tobacco-like smell, perhaps simply due
to the water adhering to them. When an attempt was made to separate
them by a filter, they entirely disappeared, being probably dissolved
by an accompanying trace of essential oil. The clear water showed an
alkaline reaction partly due to _nicotine_; this was proved by adding
a solution of tannic acid, which caused a well-marked turbidity.
Nicotianine is in our opinion a fatty acid contaminated with a little
volatile oil as in the case of Capsicum (see page 454), or Iris (see
article Rhizome Iridis).
Among the ordinary constituents of leaves, tobacco contains albumin,
resin and gum. In smoking, these substances, as well as the cellulose
of the thick midrib, would yield products not agreeable to the
consumer. The manufacturer therefore discards the midrib, and
endeavours by further preparation to ensure at least the partial
destruction of these unwelcome constituents, as well as the formation
of certain products of fermentation (ferment-oils), which may perhaps
contribute to the aroma of tobacco, especially when saccharine
substances, liquorice, or alcohol, are added in the maceration to which
tobacco is subjected.
Tobacco leaves are remarkably rich in inorganic constituents, the
proportion varying from 16 to 27 per cent. According to Boussingault,
they contain when dry about 1 per cent. of phosphoric acid, and from 3
to 5 per cent. of potash, together with 2½ to 4½ per cent. of nitrogen
partly in the form of nitrate, so that to enable the tobacco plant to
flourish, it must have a rich soil or continual manuring.[1717]
[1715] Dragendorff’s _Jahresbericht_, 1874. 98.
[1716] Poggiale and Marty (1870) stated hydrocyanic acid to be absent.
[1717] For further particulars on the chemistry of tobacco cultivation
see Boussingault, _Ann. de Chim. et de Phys._ ix. (1866) 50.
The lime, amounting to between a quarter and a half of the entire
quantity of ash, is in the leaf combined with organic acids, especially
malic, perhaps also citric. The proportion of potash varies greatly,
but may amount to about 30 per cent. of the ash.
=Commerce=—There were imported into the United Kingdom in the year
1872, 45,549,700 lb. of unmanufactured tobacco, rather more than half
of which was derived from the United States of America. The total value
of the commodity thus imported was £1,563,382; and the duty levied upon
the quantity retained for home consumption amounted to £6,694,037. In
1876 the consumption of tobacco had increased to 47,000,000 lb., _i.e._
1½ lb. per head of the population.
In the United States 559,049 acres of land being in 1875 under
cultivation with tobacco yielded a crop of 367,000,000 lb.
=Uses=—Tobacco has some reputation in the removal of alvine
obstructions, but it is a medicine of great potency and is very rarely
used.
=Substitutes=—Of the other species of _Nicotiana_ cultivated as
_Tobacco_, _N. rustica_ L. is probably the most extensively grown. It
is easily distinguished by its greenish yellow flowers, and its stalked
ovate leaves. In spite of their coarser texture, the leaves dry more
easily than those of _N. Tabacum_, and with some care may even be made
to retain their green colour. _N. rustica_ furnishes _East Indian
Tobacco_, also the kinds known as _Latakia_ and _Turkish Tobacco_.
_N. persica_ Lindl. yields the tobacco of Shiraz. _N. quadrivalvis_
Pursh, _N. multivalvis_ Lindl. and _N. repanda_ Willd. are also
cultivated plants, the last named, a plant of Havana, being used in the
manufacture of a much valued kind of cigar.