Galla. U. S., Br. Nutgall. Gall. [Aleppo Galls, Smyrna Galls]
"Excrescences on the young twigs of Quercus infectoria Olivier and other allied species of Quercus (Fam. Fagaceae), induced by the punctures on the leaf-buds and by the deposited ova of Cynips tinctoria Hartig (Order Hymenopterae). Not more than 5 per cent. of Galls float in water." U. S. "Galls are excrescences on Quercus infectoria, Olivier, resulting from the deposition of the eggs of Cynips gallae tinctoriae, Olivier." Br.
Galls, Syrian Galls; Galla Halepensis, s. Turcica, s. Le-antica, s. Tinctoria, s. Quercina; Galle de Chene, d'Alep, Fr. Cod.; Noix de Galle, Fr.; Gallae, P. G.; Gallapfel, Gallen, G.; Noce di galla, It.; Agalla, Sp.
Many plants, when pierced by certain insects, particularly those of the genus Cynips, are affected at the points of puncture with a morbid action, resulting in excrescences, which, as they are derived from the juices of the plant, partake more or less of its chemical character. Most of the oaks are occasionally thus affected, and the resulting excrescences, having in a high degree the astringency of the plant, have been employed for various practical purposes. They are known by the name of galls, a term which, as well as their use in medicine, has been handed down from the ancients. Quercus infectoria, Q. aegilops, Q. excelsa, Q. Ilex , Q. Cerris, and Q. Robur have been particularized as affording this product; but it is now generally admitted, on the authority of Olivier, that the official galls are derived chiefly, if not exclusively, from Q. infectoria. Under the name of Chinese galls, a product has been brought from China, supposed to be caused by an insect allied to the aphis, as such an insect has been found in the interior of them. They are irregularly spindle-shaped, often more or less bent, with obtusely pointed protuberances, about two inches long by an inch in diameter at the central thickest part, of an ash color and a soft velvety feel, very light, hollow, with translucent walls about a line in thickness, of a slight odor recalling that of ipecac, and a bitter astringent taste. From an examination of fragments of leaves and petioles found among these galls, Schenck concluded that the tree on which they are found is a species of Rhus; but according to Decaisne, their true source is probably the Distylium racemosum of Zuccarini, a large tree of Japan, the leaves of which produce a velvety gall, resembling the one in question. (Guibourt, Hist. Nat. des Drogues, 1850, iii, 703.) Daniel Hanbury asserts that this opinion of Decaisne is erroneous (P. J., Feb., 1862, p. 421), as in his examination of the packages imported from China and Japan he has found remains of different parts of a species of Rhus, but never any of a Distylium. Besides, the form of the galls of the Distylium, as figured by Siebold and Zuccarini, is entirely different. The species of Rhus which yields the commercial Chinese galls is the R. semialata Murray. The Chinese make great use of this product both in dyeing and as a medicine. L. A. Buchner, Jr., has found it to contain 65 per cent. of tannic acid identical with that of the official galls. (Ph. Cb., July, 1851, p. 526.) It is recommended by Stenhouse for the manufacture of gallic acid, being preferable for this purpose to the official galls, in consequence of its less amount of coloring matter. (P. J., Dec., 1862.) An inferior kind of galls is produced in great quantities in England, by the attack of the Cynips kollari of Hartig, upon the common English oak; but they have been ascertained to contain little tannic acid, and are of little value.
Quercus infectoria, or the so-called dyer's oak, is a small tree or shrub, with a crooked stem, seldom exceeding six feet in height. The leaves are petiolate, obtusely toothed, smooth and of a bright-green color on both sides. The acorn is elongated, smooth, two or three times longer than the cup, which is sessile, somewhat downy, and scaly. This species of Quercus grows, according to Olivier, throughout Asia Minor, from the Archipelago to the confines of Persia. M. Kinnier found it also in Armenia and Kurdistan; Hardwicke observed it growing in the neighborhood of Adwanie, and it probably pervades the middle latitudes of Asia.
The gall originates from the puncture of the Cynips tinctoria Hartig, a hymenopterous insect or fly, with a fawn-colored body, dark antennae, and the upper part of its abdomen shining brown. The insect pierces the shoots and young boughs, and deposits its egg in the wound. This irritates the part, and a small tumor quickly rises, which is the result of a morbid growth, exhibiting various cells under the microscope, but no proper vegetable fiber. The egg grows with the gall, and is soon converted into a larva, which feeds upon the vegetable matter around it, and thus form a cavity in the center of the excrescence. The insect at length becomes a fly, and escapes by eating its way out. The galls are in perfection when fully developed, before the egg has been hatched or the fly has escaped. Collected at this period, they are called, from their dark color, blue, green, or black galls, and are most highly esteemed. Those which are gathered later and have been injured by the insect are white galls. They are usually larger, less heavy and compact, and of a lighter color than the former.
The galls collected in Syria and Asia Minor are brought to this country chiefly from the ports of Smyrna and Trieste, or from London. As they are produced abundantly near Aleppo, it has been customary to designate them by the name of that town, though the designation, however correct it may formerly have been, is now wholly inapplicable, as they are obtained from many other places, and the product of different parts of Asiatic Turkey is not capable of being discriminated, at least in our markets. Great quantities of galls, very closely resembling those from the Mediterranean, have been brought to the United States from Calcutta. Royle states that they are taken to Bombay from Bussorah through the Persian Gulf. "We are, nevertheless, informed that galls are among the products of Moultan. Those of France and other southern countries of Europe have a smooth, shining reddish surface, are little esteemed, on account of their small yield of tannin, and are seldom brought to the United States.
Properties.—Galls are "nearly globular, from 0.8 to 2.2 cm. in diameter; externally blackish-olive-green or blackish-gray, more or less tuberculated on the upper portion, the basal portion being nearly smooth and contracted into a short stalk; heavy, sinking in water, excepting the smaller galls; fracture short-horny; internally grayish or dark brown, consisting of a central portion slightly radiating and resinous, occasionally hollow and traversed by a narrow radial canal extending to the exterior as shown by the perforation in the whole gall; odor slight; taste strongly astringent. The powder consists of numerous fragments of thick-walled starch-bearing parenchyma; starch grains numerous; more or less free in the powder and varying in shape from spherical or ellipsoidal to polygonal, and from 0.005 to 0.03 mm. in diameter; stone-cells few, resembling those found in fruits and seeds, varying considerably in shape and size, and from 0.025 to 0.3 mm. in length; occasional fragments with spiral or reticulate tracheae; fragments mounted in dilute ferric chloride T.S. assume a deep blue or greenish-blue color. Macerate 0.5 Gm. of the powdered Nutgall with 2 mils of alcohol for a few minutes, add 500 mils of water, stir the mixture well for five minutes and filter. Take 1 mil of the light yellowish-brown -solution, and dilute it with 10 mils of water; it shows a distinct blue or violet-blue color upon the addition of a drop of ferric chloride T.S." U. S.
"Hard, heavy, subglobular, from twelve to eighteen millimetres or more in diameter, tuberculated on the surface, the tubercles and intervening spaces being smooth; dark bluish-green or dark olive-green externally, yellowish or brownish-white within, with a small central cavity. Galls sink in water and exhibit no perforation. No odor; taste intensely astringent." Br.
The best are externally of a dark bluish or lead color, sometimes with a greenish tinge, internally whitish or brownish, hard, solid, brittle, with a flinty fracture, a striated texture, and a small spot or cavity in the centre, indicating the presence of the undeveloped or decayed insect. Their powder is of a light yellowish-gray. Those of inferior quality are of a lighter color, sometimes reddish or nearly white, of a loose texture, with a large cavity in the centre, communicating externally by a small hole through which the fly has escaped.
Kraemer (Bot. Gaz., 1900, p. 275) made a microchemical study of American galls. These closely resemble the Aleppo variety and are formed on Quercus coccinea Muench and Q. imbricaria, Michx. by Cynips aciculata. Kraemer found the chemical constituents to vary with the development of the insects. At the chrysalis stage gallic acid is more abundant than when the winged insect is developed. Texas galls are formed on the live oak (Q. virens., California oak balls are formed on Q. lobata.
Galls are formed on a number of trees and shrubs, including oaks, rhus, rhododendron, juniper, eucalyptus and sage. Hartwich (Arch. d. Pharm., 1905, p. 584) illustrates these several varieties and discusses their composition. Richter gives minute descriptions of the origin, structural characteristics and microscopical appearance of galls in Ph. Zentralh., 1912, p. 533. Feist and Haun have published (A. Pharm., 1913, v. 251, p. 468) an article on the constitution of the tannin in Turkish and Chinese galls.
Galls have a bitter, very astringent taste, and when whole are inodorous or nearly so, but bruised or in powder they have a decided and peculiar though not very strong odor. The tannin of galls, usually known as gallo-tannic acid, appears to exist in the galls, in part at least, as a glucoside, but one very easily broken up by ferments like pectase into glucose and digallic acid, C14H10O9, which is the material, therefore, extracted from the galls. This digallic acid may be considered as the anhydride of gallic acid, C7H6O5. formed from two molecules of this latter by the elimination of one molecule of water. Commercial tannin yields from 0 to 22 per cent. of glucose, showing the presence of varying amounts of the unaltered glucoside. Galls yield, on an average, from 65 to 77 per cent. of tannin. All the soluble matter of galls is taken up by forty times their weight of boiling water, and the residue is tasteless. Alcohol dissolves seven parts in ten, ether five parts. A saturated decoction deposits upon cooling a copious pale-yellow precipitate. The infusion or tincture affords precipitates with sulphuric and hydrochloric acids, lime water, and ammonium and potassium carbonates, with solutions of lead acetate and subacetate, copper and iron sulphates, silver and mercuric nitrates, and potassio-anti-monyl tartrate; with solution of gelatin; and with the infusions of Peruvian bark, calumba, opium, and many other vegetables, especially those containing alkaloids, with most of which tannic acid forms insoluble compounds. The infusion of galls reddens litmus paper, is rendered orange by nitric acid, milky by mercuric chloride, and has its color deepened by ammonia, but yields no precipitate with either of these reagents. Zinc sulphate was said by A. T. Thomson to slowly occasion a precipitate, but this result was not obtained by Dun-can. Infusion of galls is rendered more permanent by the addition of 10 per cent. of glycerin.
A variety of galls was imported into Germany, which was said to be derived from Central Asia, especially from the provinces of Khokan, Khiva, and Bokhara, where they are used in dyeing. They are of various forms, some being long, others round, cylindrical, or angular, and sometimes they are grouped upon a single stalk, and covered with little elevations. They differ from all other galls by their color, being on one side yellow, and on the other of a fine red. Most of them present a little opening, and in the interior are eggs and larvae of a peculiar species of aphis. They have yielded, on analysis, 43.10- per cent. of tannin, 3.03 of a green wax, 16 of cellulose, and an undetermined quantity of fecula and volatile oil. (R. Palne, J. P. C., April, 1873.)
From the so-called gall-wax of certain kinds of galls, M. Nierenstein obtained a nitrogenous constituent, C13H17O6N, which is probably a laevorotatory galloleucin. (Z. Phys. Ch., 92, 53.)
Uses.—Galls have a powerfully astringent action, but are no longer prescribed internally. Aromatic Syrup of Galls is sometimes prescribed. For a process, see U. S. Dispensatory, 19th ed., p. 574. Nutgalls may be used externally for the same purposes as tannic acid.
Dose, five to fifteen grains (0.3-0.9 Gm.).
Off. Prep.—Tinctura Gallae, N. F.; Unguentum Gallae, U. S., Br.; Unguentum Gallae cum Opio, Br.; Elixir Rubi Compositum, N. F.