bolus of calomel, gamboge, scammony, and Confectio hyacinthidis,—given in the foregoing order.1

Peschier 2 of Geneva recommended as a substitute for the bulky powder of the root, an ethereal extract, an efficient preparation, which though proposed in 1825, was scarcely used in England until about 1851; at present it is the only form in which male fern is employed.

Description-The fresh rhizome or caudex is short and massive, 2–3 inches in diameter, decumbent, or rising a few inches above the ground, and bearing on its summit a circular tuft of fronds, which in their lower part are thickly beset with brown chaffy scales. Below the growing fronds are the remains of those of previous seasons, which retain in their firm, fleshy bases, vitality and succulence for years after their upper portion has perished. From among these fleshy bases, spring the black, wiry, branching roots. The rhizome is rather fleshy, and easily cut with a knife, internally of a bright pale yellowish green; it has very little odour and a sweetish astringent taste. For pharmaceutical use, it should be collected in the late autumn, winter or early spring, divested of the dead portions, split open, dried with a gentle heat, reduced to coarse powder, and at once exhausted with ether. Extract obtained in this way is more efficient than that which has been got from rhizome that has been kept some time.

Microscopic Structure-On transverse section of the rootstock, the tissue, shows rounded, somewhat polyhedral cells with porous walls; the outer cells are brown and rather smaller, but do not exhibit the regular flattened shape, usual in many suberous coats. Within this cortical layer, there is a circle of about 10 large vascular bundles, besides a large number of smaller ones scattered beyond the circle. The leaf-bases exhibit a somewhat different structure, their vascular bundles, usually 8, forming but one diffuse circle.

The cells of the parenchyme contain starch, greenish or brownish granules of tannic matter, and drops of oil. In the green, vigorously vegetating parts of the rootstock there are numerous smaller and larger intercellular spaces, into which a few stalked glands project, as shown by Prof. Schacht of Bonn in 1863. These globular glands originate from the cells bordering the intercellular spaces. After their complete development, and the appearance of starch in the adjacent parenchyme, they exude a greenish fluid, which when thin slices of the rhizome are kept some time in glycerin, solidifies in acicular crystals. Such glands appear to be wanting in most of the allied ferns, such as Aspidium Oreopteris Sw. and Asplenium Filix-femina Bernh. They have been observed by one of us (F.), in the rhizome of A. spinulosum Sw. Similar glands but not exuding a green liquid, occur between the paleæ below the vegetating cone of the rootstock.

Chemical Composition-Of the numerous examinations which have been made of this drug, those of Bock (1852), and of Luck (1860),

1 Traitement contre le Ténia ou ver solitaire, pratiqué à Morat en Suisse, examiné et éprouvé à Paris. Publié par ordre du Roi, 1775. 4, pp. 30. 3 plates, one representing the plant, its rhizome and leaves.Also English translation by Dr. Simmons, London, 1778. 8°.

2 Bibliothèque Universelle, xxx. (1825) 205; XXX. (1826) 326.

3 The chemical nature of this body remains to be ascertained. The crystals are probably Filicic Acid, accompanied by chlorophyll and essential oil.

may be especially mentioned. Besides the universally distributed constituents of plants, there have been found in the rhizome 5 to 6 per cent. of a green fatty oil, traces of volatile oil, resin, tannin (Luck's Tannaspidic and Pteritannic Acids) and crystallizable sugar, which according to Bock, is probably cane sugar.

The medicinal ethereal extract, of which the rhizome yields about 8 per cent., deposits a colourless, granular, crystalline substance, noticed by Peschier as early as 1826, and subsequently designated by Luck, Filicic Acid. Grabowski (1867) assigned it the formula, C14H1805. We learn from Prof. Buchheim that he regards filicic acid as the source of the medicinal efficacy of the drug. By fusion with potash, filicic acid is converted into phloroglucin and butyric acid. The green liquid portion of the extract consists mainly of a glyceride called Filixolin, from which Luck obtained by saponification two acids, the one volatile, Filosmylic Acid, the other non-volatile, termed Filixolic Acid.

Malin (1867) showed that the tannic acid of male fern may be decomposed by boiling dilute acids, into sugar and a red substance, Filix-red, C26H18012, analagous to Cinchona-red.

Schoonbroodt performed some interesting experiments with fresh fern root, showing that it contains volatile acids of the fatty series, among which is probably formic; but also a fixed acid, accompanied by an oil of disagreeable odour. The liquid distilled from the dried root did not evolve a similar odour, nor did it contain any acid body. A small quantity of essential oil was obtained by means of ether from the alcoholic extract of the fresh but not of the dried rootstock.

The substance called Aspidine, regarded by Pavesi as the active constituent, seems to be essentially filicic acid. The rhizome of male fern yields 2 to 3 per cent. of ash, consisting mainly of phosphates, carbonates, and sulphates of calcium and potassium, together with silica.

Uses The ethereal extract has been prescribed for all kinds of intestinal worms; but recent experience goes to prove that its effects. are chiefly exhibited in cases of tapeworm. It is equally and thoroughly efficacious in the three kinds respectively termed Tania solium, T. medio-cannellata and Bothriocephalus latus.

Substitution-The rhizomes of Asplenium Filix-fæmina Bernh., Aspidium Oreopteris Sw., and A. spinulosum Sw. may be mistaken for that of A. Filix-mas. The best means of distinguishing them is afforded by transverse sections of the leaf-bases. In Filix-mas, the section exhibits 8 vascular bundles,-in the other ferns named, only 2,-a difference easily ascertained by examination under a lens.

1 Journal de Médecine de Bruxelles, 1867 and 1868-also Wittstein's Vierteljahresschrift für prakt. Pharm. xviii. (1869) 106.

Thallogens.

LICHENES.

LICHEN ISLANDICUS.

Iceland Moss; F. Lichen ou Mousse d'Islande; G. Isländisches Moos.

Botanical Origin-Cetraria Islandica Acharius.'-It is abundant in high northern latitudes, as Greenland, Spitzbergen, Siberia, Scandinavia and Iceland, where it grows even in the plains. It is found in the mountainous parts of Great Britain, France, Italy and Spain, in Switzerland and in the Southern Danubian countries. It also occurs in North America and in the Antarctic regions.

History-In the North of Europe, this lichen has long been used under the general name of Mosi, Mossa or Mus as an article of food. Ole Borrich, of Copenhagen (1671), called it Muscus catharticus, under the notion that in early spring it possesses purgative properties. Its medicinal employment in pulmonary disorders was favourably spoken of by Hjärne in 1683,3 but it is only since 1757 that it has come into general use as a medicine, chiefly on the recommendation of Linnæus and Scopoli.

Description-The plant consists of an erect, foliaceous, branching thallus, about 4 inches high, curled, channelled or rolled into tubes, terminating in spreading truncate, flattened lobes, the edges of which are fringed with short thick prominences. The thallus is smooth, grey, or of a light olive-brown; the under surface is paler and irregularly beset with depressed white spots. The apothecia (fruits), which are not very common, appear at the apices of the thallus, as rounded boss-like bodies, to of an inch across, of a dark, rusty colour. The colour and mode of division of the thallus vary greatly, so that many varieties of the plant have been distinguished.

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In the dry state, Iceland moss is light, harsh and springy; it absorbs water in which it is placed, to the extent of a third of its weight, becoming soft and cartilaginous; it ordinarily contains about 10 per cent. of hygroscopic water. It is inodorous, but when wetted has a slight seaweed-like smell; its taste is slightly bitter.

1 Cetraria from cetra, an ancient shield of hide, in allusion to the circular apothecia. 2 Bergius, Materia Medica, Stockholm, ii. (1778) 856.

3 Murray, Apparatus Medicaminum, v. (1790) 510.

Microscopic Structure-A transverse section exhibits when strongly magnified, a broad loose central layer of long, thick-walled branching cells or hypha, containing air, and enclosing wide hollow spaces. This middle layer encloses a certain number of larger cells. called gonidia, coloured with chlorophyll. The gonidia are not destroyed either by strong sulphuric acid, or by boiling them with potash. They assume however a deep violet colour when treated with caustic potash and then left for 24 hours in a solution of iodine in potassium iodide.

The tissue on either side of this central layer consists of very thickly felted hypha, without intervening spaces, and does not appear to contain any particular substance. This compact and tenacious. tissue passes into a thin cortical layer consisting of cells very closely bound together. Under the influence of reagents this layer becomes very evident thus when moistened with strong sulphuric or hydrochloric acid, it separates from the rest of the tissue as a coherent membrane, and rolls itself backward. On boiling with water the inner tissue swells up, the cell-walls being partly dissolved. Thin slices of the lichen are coloured reddish or pale blue by iodine water, more distinctly blue, if previously treated with sulphuric acid. The colour spreads uniformly over the inner tissue, but no starch granules can be detected; the cortical layer is merely coloured brown by iodine. The white spots on the outer surface of the thallus are resolved by pressure under a plate of glass into minute round transparent granules, not coloured by iodine, and thick branched cells like those of the central layer.

The short, thick prominences on the edge of the thallus, frequently terminate in one or more sac-like cavities (spermogonia) containing a large number of simple bar-shaped cells (spermatia), only 6 mkm. long; they are enveloped in transparent mucus, and may be expelled by pressure under glass. It has been shown by Stahl (1874) that they represent the fertilizing corpuscles of seaweeds of the class Florideæ.

The observations of De Bary (1866) and Schwendener (1867–70) confirmed and much extended by the researches of Bornet1 (1873–74), have shown that the gonidia of lichens are referable to some species of Alga, and are capable of an independent existence; that the relations of the hyphæ to the gonidia are of such a nature as to exclude the possibility of either of those bodies being produced by the other; and further, that the theory of parasitism is the only one capable of explaining these relations in a satisfactory manner. Under this singular theory, lichens are compound organisms, formed of an alga, and of a fungus living upon it as a parasite.

Chemical Composition-Boiling water extracts from Iceland moss, as much as 70 per cent. of the so-called Lichenin or Lichen-starch, a body which is perfectly devoid of structure. The decoction (1: 20) gelatinizes on cooling, and assumes a reddish or bluish tint by solution of iodine. This property of lichenin is plainly seen, when the drug is first exhausted by boiling spirit of wine containing some carbonate of potassium; and then boiled with 50 to 100 parts of water, and the decoction precipitated by means of alcohol. The lichenin thus obtained in a purer state, must be deprived of alcohol by cautiously washing it with

1 Recherches sur les gonidies des Lichens.-Ann. des Sciences nat. (Bot.) xvii. (1873) 45-110, 11 plates; also xix. (1874) 314-320.

water. Powdered iodine will now immediately impart to it while still moist an intense blue. Its composition, C10H20010, agrees with that of starch and cellulose; and it must be regarded as a modification of the latter, being likewise soluble in water and in ammoniacal solution of copper. Lichenin is not a kind of mucilage, because it yields but insignificant traces of mucic acid, if treated with concentrated nitric acid; and also because it contains no inorganic constituents. The very trifling proportion of mucic acid it furnishes, may depend upon the presence, in small amount, of an independent mucilaginous body.

The chlorophyll of the gonidia is not soluble in hydrochloric acid, and hence is distinguished by Knop and Schnedermann as Thallochlor; its quantity is extremely small.

The bitter principle of cetraria, called Cetraric Acid or Cetrarin, C18H16O8, crystallizes in microscopic needles, is nearly insoluble in cold water, and forms with alkalis, yellow, easily soluble, bitter salts. The lichen also contains a little sugar, and about 1 per cent. of a peculiar body, Licheno-stearic Acid, C14H34O3, the crystals of which melt at 120° C. The Lichenic Acid found by Pfaff in 1826 in Iceland moss, and formerly regarded as a peculiar compound, has been proved identical with fumaric acid.

In common with many lichens, cetraria contains Oxalic Acid and is said to yield also some tartaric acid. The ash which amounts to 1-2 per cent., consists to the extent of two-fifths, of silicic acid combined chiefly with potash and lime.

Collection and Commerce-Iceland moss is collected in many districts where the plant abounds, at least for local use, as in Sweden, whence some is shipped to other countries. It is also gathered in Switzerland, especially on the mountains of the canton of Lucerne, and in Spain. None is exported from Iceland.

2

Uses-It is given in decoction as a mild tonic, combined with more active medicines. It is very little employed in Iceland, and only in seasons of scarcity, when it is sometimes ground and mixed with the flour used in making the grout or grain soup. Occasionally it is taken boiled in milk. It is not given, as has been asserted, to domestic animals.

An interesting application of Iceland moss has recently been tried in Sweden. Sten-Stenberg treats it with sulphuric or hydrochloric acid, when 72 per cent. of grape sugar are formed, which may be converted into alcohol.3

FUNGI.

SECALE CORNUTUM.

Ergota; Ergot of Rye, Spurred Rye; F. Seigle ergoté; G. Mutterkorn. Botanical Origin-Claviceps purpurea Tulasne, a fungus of the order Pyrenomycetes, of which ergot is an immature form, it being the 3 Dingler's Polytechnisches Journal, 197 (1870) 177; also Chemisches Centralblatt, 1870.607.

1 The various mucilages and gums yield from 4 to 20 per cent. of ash, but pure ichenin yields none.

Cat. of Spanish Productions,-London Exhibition, 1851.

4 From the French ergot, anciently argot, a cock's spur.