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best, but no attempt has been made to determine with accuracy the relative merits of the three sorts.

The

Chemical Composition-Hyoscyamine, the most important among the constituents of henbane, was obtained in an impure state by Geiger and Hesse in 1833. Höhn in 1871 first isolated it from the seeds, which are far richer in it than the leaves.1 The seeds are deprived of the fatty oil (26 per cent.) and treated with spirit of wine containing sulphuric acid, which takes out the hyoscyamine in the form of sulphate. The alcohol is then evaporated and tannic acid added; the precipitate thus obtained is mixed with lime and exhausted with alcohol. hyoscyamine is again converted into a sulphate, the aqueous solution of which is then precipitated with carbonate of sodium, and the alkaloid dissolved by means of ether. After the evaporation of the ether, hyoscyamine remains as an oily liquid which after some time concretes into wart-like tufted crystals, soluble in benzol, chloroform, ether, as well as in water. Höhn and Reichardt assign to hyoscyamine the formula, C15H23NO3. The seeds yield of it only 0.05 per cent.

Hyoscyamine is easily decomposed by caustic alkalis. By boiling with baryta in aqueous solution, it is split into Hyoscine, C6H13N, and Hyoscinic Acid, C9H10O3. The former is a volatile alkaloid; hyoscinic acid, a crystallizable substance having an odour resembling that of empyreumatic benzoic acid.2

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Attfield has pointed out, that extract of henbane is rich in nitrate of potassium and other inorganic salts. In the leaves, the amount of nitrate is, according to Thorey, largest before flowering, and the same observation applies to hyoscyamine.

Uses-Henbane in the form of tincture or extract is administered as a sedative, anodyne or hypnotic. The impropriety of giving it in conjunction with free potash or soda which render it perfectly inert, has been demonstrated by the experiments of Garrod.5 Hyoscyamine, like atropine, powerfully dilates the pupil of the eye.

Substitutes-Hyoscyamus albus L., a more slender plant than H. niger L., with stalked leaves and bracts, a native of the Mediterranean region, is sometimes used in the south of Europe as medicinal henbane. H. insanus Stocks, a plant of Beluchistan, is mentioned in the Pharmacopoeia of India as of considerable virulence, and sometimes used for smoking.

FOLIA TABACI.

Herba Nicotiana; 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

1 From the experiments of Schoonbroodt. (1868), there is reason to believe that the active principle of henbane can be more easily extracted from the fresh than from the dried plant.

2 I have had the opportunity of examining

the above substances as prepared by the
said chemists.-F. A. F., July 1871.
3 Pharm. Journ. iii. (1862) 447.
Wiggers and Husemann, Jahresbericht
1869. 56.

5 Pharm. Journ. xvii. (1858) 462; xviii. (1859) 174.

state.

Its cultivation is carried on in most temperate and sub-tropical

countries.

History-It is stated by Von Martius 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.2

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,3 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 this 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.1

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Monardes 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.

Jacques Gohory 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.

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The cultivation of tobacco in England, except on a very small scale in a physic garden, has been prohibited by law 1 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 pharmacopoeias 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. 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 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.

Nicotine is a colourless oily liquid, of sp. gr. 1·027 at 15° C.; it boils at 250° C., 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. Most salts of nicotine crystallize with difficulty; its hydrochlorate forms with chloride of zinc a compound obtainable in crystals of considerable size. Nicotine is the highly poisonous principle of tobacco; it occurs in the dried leaves to the extent of about 6 per cent., but is subject to great variation. 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, sulphuretted hydrogen, several volatile fatty acids, phenol and creasote. There was further observed in

1 12 Car. II. c. 34; 15 Car. II. c. 7.For further information on the history of

tobacco, see Tiedemann, Geschichte des Ta baks, Frankfurt, 1854.

the imperfect combustion of tobacco, the formation of laminæ fusible at 94° C. and having the composition C19H18.

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.

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 2 to 4 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.

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 £1,563,882; and the duty levied upon the quantity retained for home consumption, amounted to £6,694,037.

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.

SCROPHULARIACEÆ.

FOLIA DIGITALIS.

Foxglove Leaves; F. Feuilles de Digitale; G. Fingerhutblätter. Botanical Origin-Digitalis purpurea L., an elegant and stately plant, common throughout the greater part of Europe, but preferring siliceous soils and generally absent from limestone districts. It is found on the edges of woods and thickets, on bushy ground and commons, becoming a mountain plant in the warm parts of Europe. It occurs in Central and Southern Spain, Northern Italy, France, Germany, the British Isles and Southern Sweden, and in Norway as far as 62° N. lat.; it is however very unequally distributed, and is altogether wanting in the Swiss Alps and the Jura. As a garden plant it is well known.

History-We are acquainted with no very ancient accounts of the use of foxglove in medicine. Fuchs 2 and Tragus about the middle of the 16th century figured the plant; the former gave it the name Digitalis, remarking that up to the time at which he wrote, there was none for the plant in either Greek or Latin. At that period it was regarded as a violent medicine. It had a place in the London Pharmacopoeia of 1650 and in several subsequent editions. The investigation of its therapeutic powers (1776-9) and its introduction into modern practice are chiefly due to Withering, a well-known English botanist and physician.*

The word foxglove is said to be derived from the Anglo-Saxon Foxesglew, i.e. fox-music, in allusion to an ancient musical instrument consisting of bells hung on an arched support.5

Description-Foxglove is a biennial or perennial, the leaves of which ought to be taken from the plant while in full flower. The lower leaves are ovate with the lamina running down into a long stalk; those of the stem become gradually narrower, passing into ovate-lanceolate with a short broadly-winged stalk, or are sessile. All have the margin crenate, crenate-dentate, or sub-serrate, are more or less softly pubescent or nearly glabrous on the upper side, much paler and densely pubescent on the under, which is marked with a prominent network of veins. The principal veins diverge at a very acute angle from the midrib, which is thick and fleshy. The lower leaves are often a foot or more long, by 5 to 6 inches broad; those of the stem are smaller.

1 Dr. R. O. Cunningham found (1868) Digitalis purpurea completely naturalized about San Carlos in the Island of Chiloe in Southern Chili.

De Hist. Stirpium, 1542. 892.

3 De Stirpium nomenclaturis, etc. 1552-"Campanula sylvestris seu Digitalis." 4 Withering (William), Account of the Foxglove, Birmingham, 1785. 8°.

5 Prior, Popular Names of British Plants, ed. 2. 1870. 84.

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