RHIZOMA FILICIS.

Botanical Origin—Aspidium Filix mas Swartz (Polypodium L. Nephrodium Michaux). The male fern is one of the most widely distributed species, usually growing in abundance and, in temperate regions, ascending as high as the arborescent vegetation. It occurs all over Europe from Sicily to Iceland, in Greenland, throughout Central and Russian Asia to the Himalaya and Japan; is found throughout China, and again in Java and the Sandwich Islands, as well as in Africa from Algeria to the Cape Colony and Mauritius. In North America it is wanting in the Eastern United States, being principally replaced by the nearly allied Aspidium marginale Sw. and A. Goldieanum Hook.; but it is met with in Canada, California and Mexico, as well as in New Granada, Venezuela, Brazil, and Peru.

History—The use of the rhizome of ferns as a vermifuge was well known to the ancients,[2728] as Theophrastus, Dioscorides and Pliny all giving curious descriptions of the plant. The remedy would appear to have been administered also during the middle ages, for it was again noticed by Valerius Cordus,[2729] and had a place in German pharmaceutical tariffs of the sixteenth century as well as in Schröder’s Dispensatory.[2730] Yet Tragus[2731] remarks that, at least in Germany, the root was little used. It was in fact subsequently nearly forgotten until revived by the introduction of certain secret remedies for tapeworm, of which powdered male fern rhizome, combined with drastic purgatives, was a chief constituent.

A medicine of this kind was prepared by Daniel Mathieu, a native of Neuchâtel, born in 1741, who established himself as an apothecary in Berlin. His treatment for the parasite was so successful that it attracted the notice of Frederick the Great, who purchased his nostrum for an annuity of 200 thalers (£30), besides conferring upon him the dignity of Aulic Councillor.[2732]

Great celebrity was also gained for the method of treating tapeworm practised by Madame Nuffler or Nuffer, the widow of a surgeon at Murten (Morat), likewise in Switzerland, who in 1775 obtained for the secret from Louis XIV., after an inquiry by savans of the period, the sum of 18,000 livres. Her method of treatment consisted in the administration of—1. Panada made of bread with a little butter. 2. A clyster of salt water and olive oil. 3. The “spécifique”—simply powdered fern root. 4. A purgative bolus of calomel, gamboge, acammony, and Confectio hyacinthidis,—given in the foregoing order.[2733]

J. Peschier,[2734] a pharmacien 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. Peschier already observed a crystallized deposit in his extract.

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.[2735] 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.[2736] Such glands appear to be wanting in most of the allied ferns, such as Aspidium Oreopteris Sw. and Asplenium Filix fœmina Bernh. They have been observed by one of us (F.), in the small 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), of Luck (1860), and of Kruse (1876), 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 C₁₄H₁₈O₅. 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, C₂₆H₁₈O₁₂, analogous to Cinchona-red.

Schoonbroodt[2737] 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 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 Tænia solium, T. medio-cannellata and Bothriocephalus latus.

Substitution—The rhizomes of Asplenium Filix fœmina Bernh., Aspidium montanum Vogl. (A. Oreopteris Sw.) and A. spinulosum Sw. may scarcely 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. Practically, no other indigenous fern than A. Filix mas affords a rhizome of sufficient bulk so as to be remunerative. We are not acquainted with that of the American Aspidium marginale Swartz, the section of which shows 6 vascular bundles; its extract is stated by Cressler (1878) to be perfectly active.