LABIATE.

FLORES LAVANDULÆ.

Lavender Flowers; F. Fleurs de Lavande; G. Lavendelblumen.

Botanical Origin-Lavandula vera DC., a shrubby plant growing in the wild state from 1 to 2 feet high, but attaining 3 feet or more under cultivation. It is indigenous to the mountainous regions of the countries bordering the western half of the Mediterranean basin. Thus it occurs in Eastern Spain, Southern France (extending northward to Lyons and Dauphiny), in Upper Italy, Corsica, Calabria and Northern Africa, on the outside of the olive region. In cultivation, it grows very well in the open air throughout the greater part of Germany and as far north as Norway and Livonia.

History-There has been much learned investigation in order to identify lavender in the writings of the classical authors, but the result has not been satisfactory, and no allusion has been found which unquestionably refers either to L. vera or to L. Spica

The earliest mention of lavender that we have observed, occurs in the writings of the abbess Hildegard,3 who lived near Bingen on the Rhine during the 12th century, and who in a chapter De Lavendula alludes to the strong odour and many virtues of the plant. In a poem of the school of Salerno entitled Flos Medicina occur the following lines:"Salvia, castoreum, lavendula, primula veris,

4

Nasturtium, athanas hæc sanant paralytica membra.”

Lavender was well known to the botanists of the 16th century.

Description-The flowers of Common Lavender are produced in a lax terminal spike, supported on a long naked stalk. They are arranged in 6 to 10 whorls (verticillasters), the lowest being generally far remote from those above it. A whorl consists of two cymes, each having when fully developed, about three flowers, below which is a rhomboidal acuminate bract, as well as several narrow smaller bracts belonging to the particular flowers. The calyx is tubular, contracted towards the mouth, marked with 13 nerves and 5-toothed, the posterior tooth much. larger than the others. The corolla of a violet colour is tubular, twolipped, the upper lip with two, the lower with three lobes. Both corolla and calyx as well as the leaves and stalks, are clothed with a dense. tomentum of stellate hairs, amongst which minute shining oil-glands can be seen by the aid of a lens.

The flowers emit when rubbed a delightful fragrance, and have a pleasant aromatic taste. The leaves of the plant are oblong linear, or lanceolate, revolute at the margin and very hoary when young.

For pharmaceutical use or as a perfume, lavender flowers are stripped from the stalks and dried by a gentle heat. They are but seldom

1 On Mont Ventoux near Avignon, the region of Lavandula vera is comprised according to Martins, between 1500 and 4500 feet above the sea-level.-Ann. des Sc. Nat., Bot. x. (1838) 145. 149.

2 F. de Gingins-Lassaraz, Hist. des Lavandes, Genève et l'aris, 1826.-Lavandula

Stochas L. is however distinctly referred to both by Dioscorides and Pliny.

3 Opera Omnia, accurante J. P. Migne, Paris, 1855. 1143.

4 S. de Renzi, Collectio Salernitana, Napoli, i. 417-516.

kept in the shops, being grown almost entirely for the sake of their essential oil.

Production of Essential Oil-Lavender is cultivated in the parishes of Mitcham, Carshalton and Beddington and a few adjoining localities, all in Surrey, to the extent of about 300 acres. It is also grown at Market Deeping in Lincolnshire, and at Hitchin in Hertfordshire, at which latter place there were in 1871 about 50 acres so cropped. The plants which are of small size, and grown in rows in dry open fields, flower in July and August. The flowers are usually cut with the stalks of full length, tied up in mats, and carried to the distillery there to await distillation. This is performed in the same large stills that are used for peppermint. The flowers are commonly distilled with the stalks as gathered, and either fresh, or in a more or less dry state. A few cultivators distil only the flowering heads, thereby obtaining a superior product. Still more rarely, the flowers are stripped from the stalks, and the latter rejected in toto. According to the careful experiments of Bell,1 the oil made in this last method is of exceedingly fine quality. The produce he obtained in 1846, was 26 ounces per 100 Hb. of flowers, entirely freed from stalks; in 1847, 25 ounces; and in 1848, 20 ounces the quantities of flowers used in the respective years were 417, 633, and 923 tb. Oil distilled from the stalks alone, was found to have a peculiarly rank odour. In the distillation of lavender, it is said that the oil which comes over in the earlier part of the operation is of superior flavour.

We have no accurate data as to the produce of oil obtained in the ordinary way, but it is universally stated to vary extremely with the season. Warren gives it as 10 to 12 b., and in an exceptional case as much as 24 lb. from the acre of ground under cultivation. At Hitchin,3 the yield would appear to approximate to the last-named quantity. The experiments performed in Bell's laboratory as detailed above, show that the flowers deprived of stalks afforded on an average exactly 1 per cent. of essential oil.

Oil of Lavandula vera is distilled in Piedmont, and in the mountainous parts of the South of France, as in the villages about Mont Ventoux near Avignon, and in those some leagues west of Montpellier (St. Guilhen-le-désert, Montarnaud and St. Jean de Fos),in all cases from the wild plant. This foreign oil is offered in commerce of several qualities, the highest of which commands scarcely one-sixth the price of the oil produced at Mitcham. The cheaper sorts at least are obtained by distilling the entire plant.

Chemical Composition-The only constituent of lavender flowers that has attracted the attention of chemists, is the essential oil (Oleum Lavandula). It is a pale yellow, mobile liquid, varying in sp. gr. from 0.87 to 0.94 (Zeller), having a very agreeable odour of the flowers and a strong aromatic taste. The oil distilled at Mitcham (1871) we find to rotate the plane of polarization 4:2° to the left, in a column of 50mm. Oil of lavender is a mixture in variable proportions of a hydro

1 Pharm. Journ. viii. (1849) 276. Ibid. vi. (1865) 257.

3 Ibid. i. (1860) 278. The statement is

that an acre of land yields "about 6 Winchester quarts" of oil.

4 The Mitcham oil fetches 30s. to 60s. per b., according to the season.

carbon, C10H16, and stearoptene, the first of which boils at 200°-210° C. The stearoptene is identical according to Dumas, with common camphor. In some samples it is said to exist to the extent of one-half. It is sometimes deposited from the oil in cold weather; we have not however been able to ascertain this fact.

Commerce-Dried lavender flowers are the object of some trade in the south of Europe. According to the official Tableau général du Commerce de la France, Lavender and Orange Flowers (which are not separated) were exported in 1870 to the extent of 110,958 kilo. (244,741 fb.),—chiefly to the Barbary States, Turkey and America. There are no data to show the amount of oil of lavender imported into England.

Uses-Lavender flowers are not prescribed in modern English medicine. The volatile oil has the stimulant properties common to bodies of the same class and is much used as a perfume.

Other Species of Lavender.

1. Lavandula Spica DC. is a plant having a very close resemblance to L. vera, of which Linnæus considered it a variety, though its distinctness is now admitted. It occurs over much of the area of L. vera, but does not extend so far north, nor is it found in such elevated situations, or beyond the limit of the olive. It is in fact a more southern plant and more susceptible to cold, so that it cannot be cultivated in the open soil in Britain except in sheltered positions. In Languedoc and Provence, it is the common species from the sea-level up to about 2000 feet, where it is met by the more hardy L. vera.1

Lavandula Spica is distilled in the south of France, the flowering wild plant in its entire state being used. The essential oil which is termed in French Essence d'Aspic, is known to English druggists as Oleum Lavandula spice, Oleum Spice, or Oil of Spike. It resembles true oil of lavender, but compared with that distilled in England, it has a much less delicate fragrance.2 In chemical composition, it agrees with oil of Lavandula vera. Oil of Spike is used in porcelain painting and in veterinary medicine.

2. Lavandula Stochas L.-This plant was well known to the ancients; Dioscorides remarks that it gives a name to the Stoechades, the modern isles of Hières near Toulon, where the plant still abounds. It has a wider range than the two species of Lavandula already described, for it is found in the Canaries and in Portugal, and eastward throughout the Mediterranean region to Greece and Asia Minor. It may at once be known from the other lavenders by its flower-spike being on a short stalk, and terminating in 2 or 3 conspicuous purple bracts.

The flowers, called Flores Stachados or Stachas Arabica,3 were formerly kept in the shops, and had a place in the London Pharmacopoeia down

1 On the high land between Nice and Turbia, I have observed the two species growing together, and that L. vera is in flower two or three weeks earlier than L. Spica.-D. H.

Yet we find that flowers of the two

plants (L. vera and L. Spica) grown side by side in an English garden, are hardly dis tinguishable in fragrance.

The incorrectness of the term Arabica is noticed by Pomet. How it came to be applied we know not.

to 1746. We are not aware that they are, or ever were, distilled for essential oil, though they are stated to be the source of True Oil of Spike.1

HERBA MENTHA VIRIDIS.
Spearmint.

Botanical Origin-Mentha viridis L. is a fragrant perennial plant, chiefly known in Europe, Asia and North America, as the Common Mint of gardens, and only found apparently wild in countries where it has long been cultivated. It occurs occasionally in Britain under such circumstances.2

Mentha viridis is regarded by Bentham as not improbably a variety of M. silvestris L., perpetuated through its ready propagation by suckers. J. G. Baker remarks, that while these two plants are sufficiently distinct as found in England, yet continental forms occur which bridge over their differences.3

History-Mint is mentioned in all early mediaval lists of plants, and was certainly cultivated in the convent gardens of the 9th century. Turner, who has been called "the father of English botany," states in his Herball that the garden mint of his time was also called “Spere Mynte." We find spearmint also described by Gerarde who terms it Mentha Romana vel Sarracenica, or Common Garden Mint, but his statement that the leaves are white, soft, and hairy does not well apply to the plant as now found in cultivation.

Description-Spearmint has a perennial root-stock which throws out long runners. Its stem 2 to 3 feet high is erect, when luxuriant branched below with short erecto-patent branches, firm, quadrangular, naked or slightly hairy beneath the nodes, often brightly tinged with purple. Leaves sessile or the lower slightly stalked, lanceolate or ovatelanceolate, rounded or even cordate at the base, dark green and glabrous above, paler and prominently veined with green or purple beneath, rather thickly glandular, but either quite naked or hairy only on the midrib and principal veins, the point narrowed out and acute, the teeth sharp but neither very close nor deep, the lowest leaves measuring about 1 inch across by 3 or 4 inches long. Inflorescence a panicled arrangement of spikes, of which the main one is 3 or 4 inches long by 3 inch wide, the lowest whorls sometimes an inch from each other and the lowest bracts leafy. Bracteoles linear-subulate, equalling or exceeding the expanded flowers, smooth or slightly ciliated. Pedicels about line long, purplish glandular, but never hairy. Calyx also often purplish, the tube campanulato-cylindrical, line long, the teeth lanceolatesubulate, equalling the tube, the flower part of which is naked, but the teeth and often the upper part clothed more or less densely with erectopatent hairs. Corolla reddish-purple, about twice as long as the calyx, naked both within and without. Nut smooth.

1 Pereira, Elem. of Mat. Med. ii. (1850) 1368. Nor do we know if L. lanata Boiss. a very fragrant species closely allied to L. Spica DC., and a native of Spain, is distilled in that country.

* Bentham, Handbook of the British Flora, 1858. 413.-Parkinson (1640) remarks of

Speare Mint that it is "onely found planted in gardens with us."

3 Seemann's Journ, of Bot. Aug. 1865. p. 239. We borrow Mr. Baker's careful description of M. viridis.

4 Part 2. (1568) 54.

The plant varies slightly in the shape of its leaves, elongation of spike and hairiness of calyx. The entire plant emits a most fragrant odour when rubbed, and has a pungent aromatic taste.

Production-Spearmint is grown in kitchen gardens, and more largely in market gardens. A few acres are under cultivation with it at Mitcham, chiefly for the sake of the herb, which is sold mostly in a dried state.

The cultivation of spearmint is carried on in the United States in precisely the same manner as that of peppermint, but on a much smaller scale. Mr. H. G. Hotchkiss of Lyons, Wayne County, State of New York, has informed us that his manufacture of the essential oil amounted in 1870 to 1162 lb. The plant he employs appears from the specimen with which he has favoured us, to be identical with the spearmint of English gardens, and is not the Curled Mint (Mentha crispa) of Germany.

Chemical Composition-Spearmint yields an essential oil (Oleum Mentha viridis) in which reside the medicinal virtues of the plant. Kane who examined it, gives its sp. gr. as 0.914, and its boiling point as 160° C. The oil yielded him a considerable amount of stearoptene. Gladstone found spearmint oil to contain a hydrocarbon almost identical with oil of turpentine in odour and other physical properties, mixed with an oxidized oil to which is due the peculiar smell of the plant. The latter oil boils at 225° C.; its sp. gr. is 0.951, and it was found to be isomeric with carvol, C10H140.

Uses Spearmint is used in the form of essential oil and distilled water, precisely in the same manner as peppermint. In the United States, the oil is also employed by confectioners and the manufacturers of perfumed soap.

Substitutes-Oil of spearmint is now rarely distilled in England, its high cost causing it to be nearly unsaleable. The cheaper foreign oil is offered in price-currents as of two kinds, namely American and German. Of the first we have already spoken: the second termed in German Krausemünzöl, is the produce of Mentha aquatica L. var. y crispa Bentham, a plant cultivated in Northern Germany.

HERBA MENTHE PIPERITÆ.

Peppermint; F. Menthe poivrée; G. Pfefferminze.

Botanical Origin-Mentha piperita Hudson (non Linn.), an erect, usually glabrous perennial, much resembling the Common Spearmint of the gardens, but differing from it in having the leaves all stalked, the flowers larger, the upper whorls of flowers somewhat crowded together, and the lower separate. In the opinion of Bentham it is possibly a mere variety of M. hirsuta L., with which it can be connected by numerous intermediate forms.

Peppermint rapidly propagates itself by runners, and is now found in wet places in several parts of England, as well as on the Continent. 3 Price from 1824 to 1839, 40s. to 48s.

1 Philosophical Magazine, xiii. (1838) 444. 2 Journ. of Chemical Society, ii. (1864)

per lb.