Collinsonia Canadensis, Linné.
Natural order, Labiatae.
By CHARLES NAPIER LOCHMAN, PH.G.
From an Inaugural Essay.
The thick, hard, knotty rhizome, from which the plant undoubtedly received the names stone-root and knot-root, grows horizontally but a few inches beneath the surface of the soil and attains a length of about six or eight inches. The plant seems to delight in stony soil, as it is always found in mountainous or very rocky and shady situations. At, and after the time, of flowering, the leaves have an agreeable lemon-like odor, due to volatile oil contained in glands on the under-surface. About the time that the fruit is mature, especially if the plant is so situated as to be in the direct sunlight for part of the day, the calices have an odor similar to that of caraway; whether this is due to a volatile oil or a resin I have not been able to ascertain.
Description.—Flowers in racemes, arranged in a terminal panicle. The calices and pedicels covered with stalked glands. Calyx somewhat bilabiate, becoming four-sided and much enlarged in fruit; upper lip with three sharp-pointed teeth, lower with two lanceolate lobes; hairy in the throat. Corolla light yellow, generally purple-veined and hairy on the inside, elongated, widening from the throat outwards; four upper lobes small and obtuse; lower lobe much larger, ligulate and beautifully laciniate fringed. Fertile stamens two (with rudiments of a second pair), exserted, much exceeding the corolla. Style, purple, two cleft at the apex, about the length of the fertile stamens. Ovary deeply four parted, usually ripening only two of the four nutlets. Stem simple, erect, smooth, glaucous, obtusely four angled; from two to five feet high. Leaves thin, smooth, light green above (somewhat darker in the dried state), whitish underneath, ovate, coarsely serrate, abrupt, or somewhat heart-shaped at the base, taper-pointed the under surface dotted with small, depressed glands, containing volatile oil.
The rhizome is from one to one and a half inches in thickness, four to eight inches long, irregularly branched, the upper surface marked with cup-shaped scars left by the stems of former years; on the lower surface it is covered with long, thin, brown rootlets; it has a thin, brown bark, and a very hard white wood more or less mottled with brown.
Analysis.—The drug was treated with menstrua in the order given in Dragendorff's Plant Analysis. One gram of the powdered rhizome and rootlets yielded .029 gram of ash, after being thoroughly ignited in a porcelain crucible. Fifty grams of the powdered rhizome and rootlets were macerated with 250 cc. of petroleum spirit for one week and the filtered liquid was allowed to evaporate spontaneously, when there was remaining 1.2 gram, or 2.4 per cent. of the weight of the drug employed. On heating this to 110°C. for some time, there was no loss in weight, showing the absence of an appreciable quantity of volatile oil. The residue was of a semisolid waxy consistence, melting at 40°C., soluble in boiling alcohol, from, which it was partly precipitated on cooling, and wholly on the addition of water. This appears, to be vegetable wax.
After allowing the petroleum spirit to evaporate from the powder, it was treated with 250 cc. of stronger ether and this liquid allowed to evaporate at the ordinary temperature, when .3 gram of a somewhat bitter, yellowish, resinous substance was left. On treating this with slightly acidulated water a light yellow liquid was obtained, showing negative results with potassio-mercuric iodide and other tests for alkaloids. Ferric chloride produced a greenish black precipitate which afterwards became inky. A precipitate was also formed on the addition of gelatin. The part remaining after treatment with acidulated water had all the characters of a resin and was almost completely soluble in 95 per cent. alcohol, partly soluble in a solution of potassa, and of a slight bitter taste.
After the ether had evaporated from the powder, it was macerated for eight days with alcohol, and the filtrate made up to 250 cc. Fifty cubic centimeters of this filtrate evaporated left .59 gram of extract, equal to 5.9 per cent. vegetable matter, neither soluble in petroleum spirit nor ether, but soluble in alcohol. On incinerating this extract an almost unweighable ash remained, which proved to be principally carbonate of potassium. From the remaining filtrate the alcohol was distilled off and the residue carefully dried over sulphuric acid. The yield was a slightly bitter extract, in which tannin, which turned ferric salts greenish black and precipitated gelatin, was present, but no alkaloid could be found.
The powder remaining from the last operation was then macerated for twenty-four hours with 500 cc. of water, the infusion filtered off, and the dregs washed with sufficient water to bring it up to 500 cc. On evaporating a portion of this liquid it yielded an extract equal in weight to 10 per cent. of the original quantity of the drug employed; 20 cc. of this infusion was mixed with twice its volume of alcohol, when a precipitate was formed weighing .02 gram. This precipitate dissolved in water did not reduce Fehling's solution until it had been boiled with dilute hydrochloric acid. Its concentrated solution precipitated basic acetate of lead (vegetable mucilage).
A portion of the root on being boiled with water gave, on the addition of a solution of iodine, an intensely blue color (starch).
Leaves.—Ten grams of the powdered leaves were treated in the same manner as the rhizome, excepting a larger proportion of menstruum was used in each case. The petroleum spirit yielded .3 grain, or 3 per cent. of extract consisting of waxy matter soluble in boiling alcohol, a caoutchouc-like substance soluble in ether, and a trace of volatile oil. The etherial tincture yielded .44 gram, equal to 4.4 per cent. of extract, which had little taste and odor, and on being triturated with sand and cold water gave a slightly yellowish brown solution, colored greenish black on the addition of ferric chloride. A few drops of acetic acid were then added to the liquid, which, together with the resin, was triturated for a few minutes, allowed to stand for two hours, and filtered. This liquid did not show any indication of an alkaloid upon the application of the various tests. The alcoholic tincture yielded .47 gram of a dark green extract containing tannin and chlorophyll, but no trace of an alkaloid.
About 16 lbs. of fresh leaves, collected when the plant was in full blossom, were distilled, yielding one drachm of a very light yellow volatile oil of a pleasant lemon-like odor.
From the foregoing meagre experiments the rhizome is shown to contain a resin soluble in ether and partly soluble in alcohol, vegetable wax, tannin, mucilage and starch; and the leaves resin, chlorophyll, tannin, wax and volatile oil. The volatile oil is nearly all dissipated on drying, at least after several months. It seems almost impossible that this nearly tasteless rhizome should have the wonderful properties ascribed to it by certain eclectic physicians. If any part of the plant is of any use medicinally, I would judge it to be the fresh leaves.