BALSAM. 



l.Opobalsamum. 4. Peru. 



2. Copaiva. 5. Styrax. 



3. Tolu. 



1. Opobalsamum, or balm of Gilead. 

 This balsam is obtained from the amyris 

 Gileadensijs, a tree which grows in Ara- 

 bia, especially near Mecca. It is so much 

 valued by the Turks, that it is seldom or 

 never imported into Europe. We are 

 of course ignorant of its composition. It 

 it is said to be at first turbid and white ,and 

 of a strong aromatie smell, and bitter, 

 acrid, astringent taste ; but by keeping 

 it becomes limpid and thin, and its colour 

 changes first to green, then to yellow, and 

 at last it assumes the colour of honey,aml 

 the consistence of turpentine. It is also 

 very tenacious and glutinous, sticking to 

 the fingers, and may be drawn into long 

 threads. The mode of ascertaining the 

 purity of this balsam at Cairo and Mecca 

 is, to drop it into a cup of clear cold wa- 

 ter ; if it remain in one place on the sur- 

 face, it is of little or no value, but if it ex- 

 tend itself like a skin over the whole sur- 

 face, (and this skin is even, and almost 

 transparent, and may be taken off the 

 water with a hair,) it is of great worth. 

 The balsam of Gilead principally comes 

 from Arabia Petraea, from whence the 

 Arabs carry it to Mecca for sale during 

 the stay of the caravans from Egypt and 

 Turkey. It grows also in the Holy Land, 

 but not without much culture and atten- 

 tion, whereas in Arabia it grows without 

 cultivation. It is the produce of a species 

 of the amyris, rising to the height of the 

 pomegranate tree, to which it has a 

 great resemblance, both in its branches 

 and flowers. See AMYRIS. The balsam 

 is obtained by incision during the sum- 

 mer months, flowing over in a viscous 

 juice, called Opobalsamum. It is white 

 when it comes from the tree, and changes 

 first to a green, and afterwards to a gold 

 colour. 



2. Copaiva. This balsam is obtained 

 from the Copaifera Officinalis; a tree 

 which grows in South America, and some 

 of the West Indian islands. It exudes 

 from incisions made in the trunk of the 

 tree. The juice thus obtained is trans- 

 parent, of a yellowish colour, an agreea- 

 ble smell, a pungent taste, at first of the 

 consistence of oil, but it gradually be- 

 comes as thick as honey. Its specific 

 gravity is 0.950. When mixed with wa- 

 ter and distilled, there comes over with 

 the water a very large portion of volatile 

 oil. The oil ceases to come over before 

 all the water has passed into the receiv- 

 er. The residuum of course consists of 

 two substances; namely, the watery por- 



tion, and a greyish yellow substance, 

 lying at the bottom of the vessel, which., 

 on exposure to the air, dries, ami be- 

 comes brittle and transparent. When 

 heated it melts, and possesses the cha- 

 racters of a resin. Nitric acid acts upon 

 this balsam with considerable energy. 

 When one part of the balsam is mixed 

 with four parts of nitric acid and two 

 parts of water, and heated, a yellowish so- 

 lution is formed, similar to the original 

 balsam, but darker. When distilled, there 

 comes over with the liquid that passes 

 into the receiver an apple-green oil, 

 which lines the helm of the retort. The 

 nature of the residue was not examined. 

 When treated with sulphuric acid, it 

 yields a portion of artificial tannin. Whe- 

 ther this balsam yields benzoic acid, has 

 not been ascertained : its properties are 

 rather against the probability of its doing 

 so. Indeed it bears a striking resem- 

 blance to turpentine in many respects; 

 and ought, along with it, to constitute a 

 class of bodies intermediate between vo- 

 latile oils and resins, to which the name 

 of turpentine might be given. 



3. Balsam of Tolu. This substance is 

 obtained from the Toluifera balsamum, a 

 tree which grows in South America. The 

 balsam flows from incisions made in the 

 bark. It comes to Europe in small gourd 

 shells. It is of a reddish brown colour 

 and considerable consistence, and when 

 exposed to the air it becomes solid and 

 brittle. Its smell is fragrant, and con- 

 tinues so even after the balsam has be- 

 come thick by age. When distilled with 

 water, it yields very little volatile oil. 

 but impregnates the water strongly with 

 its taste and smell. A quantity of ben- 

 zoic acid sublimes, if the distillation be 

 continued. Mr. Hatchett found it solu- 

 ble in the alkalies, like the rest of the 

 balsams. When he dissolved it in the 

 smallest possible quantity of lixivium of 

 potash, it completely loses its own odour 

 and assumes a most fragrant smell, some- 

 what resembling that of the clove j pink. 

 *' This smell," Mr. Hatchett observes, 

 " is not fugitive, for it is still retained by 

 a solution which was prepared in June, 

 and has remained in an open glass during 

 four months." When digested in sul- 

 phuric acid, a considerable quantity of 

 pure benzoic acid sublimes. When the 

 solution of it in this acid is evaporated to 

 dryness, and the residuum treated with 

 alcohol, a portion of artificial tannin is ob- 

 tained ; the residual charcoal amounts to 

 0. 54 of the original balsam. 



4. Balsam of Peru is obtained from the 

 Myroxylon Peruiferum, The tree is ful! 



