(From Gallus, a river in Bythinia,) nuces gallae, gallae maxima orbiculattae, gallae spinosae, ceses, galls; the productions of the quercus cerris Lin. Sp. Pl. 1415.

They are hard round excrescences; the nests of an insect called cynips, found in the warmer countries on the oak tree. The tear which issues from the wound, made by the insect, gradually increased by accessions of fresh matter, forms a covering to the eggs and succeeding insects. Those galls which have no aperture contain the dead insects. Two sorts are distinguished in the shops; one said to be brought from Aleppo, galla spinosa; the other from the southern parts of Europe, called European galls. The former are generally of a bluish, greyish, or blackish colour, and verging to a blue, unequal in their surface, difficult to break, and of a close texture: the others are of a pale brownish or whitish colour, smooth, round, easily broken, less compact, and of a much larger size. The two sorts differ in strength; but in other respects are of the same quality: the small, protuberant, bluish, and heavy ones are the best.

Galls are supposed to be the strongest astringent in the vegetable kingdom, without any other smell or taste. Both water and spirit take up nearly all their virtue, though the spirituous extract is the strongest preparation. The powder is, however, the best form; and the dose is from a few grains to half a drachm.

They are not much used in medicine, though they are said to be beneficial in intermittents. Dr. Cullen has cured agues,by giving half a drachm of the powder of galls every two or three hours, during the intermission; and by it alone, or joined with camomile flowers, has prevented the return of the paroxysms. A fomentation, made by macerating half an ounce of.bruised galls in a quart of boiling water for an hour, has been found useful for the piles, the prolapsus ani, and the fluor albus, applied cold. An injection simply astringent is made by diluting this fomentation, and used in gleets and leucorrhoea. The camphorated ointment of galls has been found also serviceable in piles after the use of leeches, and is made by incorporating half a drachm of camphor with one ounce of hog's lard, and adding two drachms of galls in very fine powder. Galls are also employed for making black writing ink, and the colouring matter for dyeing black. The decoction of galls is more rough and astringent to the taste; but an infusion in cold water strikes a deeper black with green vitriol. This is not, however, always an accurate test of the degree of astringency. For the properties of the gallic acid, see Chemistry.

See Lewis's Materia Medica. Neumann's Chemical Works. Cullen's Materia Medica.