By P. L. Simmonds, F.L.S.
There are very many of these which deserve special detailed notice, at all events as to their medicinal uses and statistics.
Four subdivisions might be established under which all the varieties of gums and resins might be grouped:
(4) Elastics and gums.
The first would include all gums, wholly or partially soluble in water, whether of the Acacia or Tragacanth kind.
The second would include resins more or less soluble in alcohol, such as copals, mastics and gum resins, like asafoetida and ammoniacum.
The third would include turpentine, wood oil and balsams.
The fourth would contain India-rubber, balata and gutta-percha, with substances of a similar character.
A resin is entirely soluble in alcohol, but insoluble in water. A gum resin is intermediate in character between a gum and a resin; that is to say, it is partly soluble in water and partly soluble in alcohol.
A kino is the astringent inspissated sap of a tree.
The resins may be divided into four groups:
(1) Solid or dry resins.
(4) Soft resins.
Perhaps it is better to arrange the products alphabetically under their botanic names.
Abies balsamea, Marshall; Abies balsamifera, Michaux; Pinus balsamea, Lin.
Canada balsam is an oleo-resin produced from the stem of this tree by incision, and is also yielded by Pinus Fraseri, Pursh [Abies fraseri].
It is of a pale straw color, and is occasionally used medicinally, but is chiefly employed for mounting objects for the microscope, and as a fine transparent varnish for water-color drawings, which does not become darker with time.
Abies excelsa, Poiret; Pinus picea, Du Roi.
Pinus Abies, Lin. [Picea abies] The resinous exudation of the Norway spruce fir, melted and strained, furnishes the concrete oleo-resin, true Burgundy pitch, the Thus or Frankincense of the London Pharmacopceia. The common frankincense or American Thus is from Pinus palustris, Lambert; Pinus Taeda, Lindl. It acts as a counterirritant, and is applied to the chest in chronic pulmonary complaints, to the loins in lumbago, and to other parts to relieve local pains of a rheumatic character.
The Indian gums are coming in largely into European commerce to supplement the African gums, the exports of gums for India having averaged 37,000 cwt. in each of the last five years. The African gums may be recognized from Indian gums by an expert, being of a different shade of color, often with a pinkish hue. The imports of gum arabic into the United States have declined by more than one-half of late years; in 1892 they were only 417,000 pounds, but recovered in 1893 to 915,855 pounds.
Acacia Catechu, Willd. The extract from this tree, known as "cutch," is used medicinally as an astringent, in fevers and other maladies, and the better qualities are equally as good medicinally as the Gambier of Singapore.
There are several kinds of cutch made in India and used in medicine.
A resinous extract is prepared by boiling down chips of the wood.
In Burma and Bombay the decoction is boiled down to a solid consistence and thrown into leaf moulds, or is baked into cakes and balls. This is the ordinary cutch of commerce, and instead of being a pale grayish color, it is deep reddish-brown, with a glassy fracture.
Another inferior kind is made from a decoction of the nut of the betel palm (Areca Catechu.) This form exists in large slabs, about an inch in thickness, prepared on the leaves of the Teak tree. This substance is, however, rarely exported from India, but a considerable local trade is carried on in it in Madras and Mysore.
Cutch is prepared thus:
The tree is cut down to about six or twelve inches from the ground and chopped into small pieces, the smaller branches and bark being rejected. The chopped wood is then taken to the place of manufacture, generally under trees in the open air, and placed over a brisk fire in clay jars, filled with about two-thirds of water.
This is allowed to boil down till, with the extracted matter, it forms a liquid of a syrupy consistence. The contents of several jars are then poured into a larger jar, and again placed over a brisk fire for a period of from two to four hours, and, when sufficiently boiled down, it is poured over mats covered with ashes of cowdung and allowed to dry.
Catechu is used in medicine as a gentle tonic and a powerful astringent, on account of the large quantity of tannic acid (50 per cent.) which it contains. Combined with opium it answers a good purpose as an internal remedy in chronic diarrhoea, catarrh or dysentery.
Cutch is not specified in the American imports, but gambier is named, but appears among gums, with the old misnomer of "Terra japonica." The quantity imported fluctuates between 27,000,000 and 35,000,000 pounds.
Sugars.—The maple tree, several palms, the white beet root, sorghums, the sugar cane, and other plants and trees, yield saccharine saps, but as the product of these have chiefly dietetic uses, rather than medicinal, I shall not enter into details on them.
Aloes Species.—The simply inspissated juice of the leaves of various species of this gum constitutes the "aloes" drug of pharmacy. It is best obtained by using neither heat nor pressure for extracting the sap. By redissolving the aqueous part in cold water and reducing the liquid through boiling to dryness, the extract of aloes is prepared. All species are valuable in localities where they are hardy, and can be used (irrespective of their medicinal importance) to beautify any rocky or otherwise arid spot.
Aloe Ferox, Lamarck.—This yields the best Cape aloes, as observed by Dr. Pappe. Other species, such as A. perfoliata, Lin., also yield the drug. A. africana, Mill., and A. plicatis, Mill., and A. commelini, Salm. [Aloe perfoliata], are said to yield a less powerful kind.
The following are also South African species: A. arborescens, Miller; A. linguaeformis, Mill. [Aloe plicatilis]; A. angulata, Willd. [Gasteria carinata]. From this species the purest gum resin is obtained.
A. purpurascens, Haworth [Aloe succotrina], is one of the plants which furnish the Cape aloes of commerce. A. spicata, Lin., also provides Cape aloes. A. Zeyheri, Harvey ([There's A. zeyheri Hort. ex Baker and A. zeyheri Salm-Dyck, but no A. zeyheri Harvey. -Henriette]), a magnificent, very tall species, is doubtless valuable like the rest. A. soccotrina, Lamarck., is also indigenous to South Africa; A. dichotoma, Lin. fil., in Damara and Namaqualand, attains a height of 30 feet and expands occasionally with its branches so far as to give a circumference of 40 feet. The stem is remarkably smooth, with a girth sometimes of 12 feet. It is a yellow-flowering species. A. Bainesii, Baker and Dyer [Aloe barberae], is almost as gigantic as the foregoing. Both, doubtless, yield the medicinal gum resin, like several others.
In many parts of the Colony of Natal, a wild aloe is very abundant, and a few people make an industry of the preparation of the product for export. Shipments, of late years, have reached £400 in value. Small balls of it were shown in the Natal Court at the Colonial Exhibition in London.
A. indica, Royle [Aloe vera].—There are many varieties of aloe met with in cultivation throughout India, some of which have gone wild, as, for example, on the coast of South India. The inspissated juice, as a medicine, is regarded as an aperient and deemed highly beneficial to persons predisposed to apoplexy. The fresh juice from the leaves is said to be cathartic, cooling and useful in fevers, spleen and liver disease, enlarged lymphatic glands, and as an external applicant in certain eye diseases. The pulp of the leaves is, in native practice in India, applied to boils and is regarded as acting powerfully on the uterus. It is largely employed in veterinary medicine. The root is supposed to be efficacious in colic. A. soccotrina, Lamarck; A. vera, Miller, is usually imported in skins and casks from Bombay. Soccotrina aloes may be recognized by its reddish tint and by the fragments being nearly transparent, as well as by its odor. A. Perryi, Baker, is indigenous to the island of Socotra. In very large doses it is a powerful hepatic stimulant. In small doses the drug is used as a stomachic tonic, in larger doses purgative and, indirectly, emmenagogue. It is a remedy of great value in constipation caused by hysteria and atony of the intestinal muscular coat. It is also very useful in atonic dyspepsia, jaundice, amenorrhoea and chlorosis. Locally applied, dissolved in glycerin, it is valued in India as a stimulant application in skin diseases, and, for this purpose, is generally combined with myrrh, constituting the Musanbar of Bombay.
Hepatic aloes is a species of Arabian aloes, so called from its liver hue. It is duller and more opaque in color than other kinds, more bitter, and has a less pleasant aroma than the Socotrine aloes itself, but is believed to be the sediment deposited in Socotrine aloe juice.
A. vulgaris, Lamarck and Bauhin [Aloe vera]; A. vera, Lin.; A. Barbadensis, Miller [Aloe vera], has long been cultivated in the Antilles, and furnishes from thence the main supply of the Barbadoes and Curacoa aloes.
This West Indian aloes may at once be distinguished by its disagreeable odor.
There are two varieties met with in commerce, one presenting a brown, the other a black fracture; the former is the best.
The culture in Barbadoes is confined to the small farmers entirely, and is carried on chiefly in the parish of St. Philip, towards the seashore, where the soil is scanty and dry. The produce of an acre of land is about 140 pounds of extract. The plants require to be renewed about every fourth year.
It is this species which Professors Willkolm and Parlatore record as truly wild in countries around the Mediterranean Sea, on the sandy or rocky sea coasts of Spain and Italy. Haworth found the leaves of this and of A. striata, more succulent than those of any other aloe.
Barbadoes aloes is usually imported in gourds, breaks with a dull conchoidal fracture, and has a bitter taste. Socotrine breaks with an irregular or smooth and resinous fracture, has a bitter taste and a strong but fragrant odor.
In my work on "The Commercial Products of the Vegetable Kingdom," published as far back as 1853, I described the production and commerce in Aloes, but much information has been published since then. The imports into London have been falling off of late years.
In 1890 the receipts were 7,360 cases and packages and 622 gourds; in 1892, they were only 2,652 cases and 277 gourds.
Anacardium occidentale, Lin.—The trunk and branches of the cashew-nut tree yield, on being wounded, during the monthly ascent of the sap, a white and transparent gum, similar to that of arabic. A full-grown tree will furnish an annual amount of ten or twelve pounds. The fresh acid juice of the flower stalks is used in lemonade; wine and vinegar are made by fermenting it.
Anogeissus latifolia. Wall.—The gum from this Indian tree occurs in clear, straw-colored, elongated tears, adhering in masses, sometimes honey-colored, or even brown from impurities. As an adhesive gum it is inferior in strength to gum arabic, in consequence of which it commands a much lower price in Europe, the more so since it is nearly always mixed with the bark of the tree, sand and other impurities.