Concerning the secretion of the balsam, next to nothing is known. Early accounts speak of a superior article obtained by making incisions in the bark and probably reaching into the wood, but the present method of gathering the balsam is universally as follows :—After the last rains, in November-Decomber, the trunks of the trees are beaten with some blunt instrument iu four equi distant patchrs until the bark is loosened, a similar number of intermediate patches being left unbruised for the following year. The injured bark splits up, and may he easily detached ; it already exhibits a slight exudation of fragrant balsam, but not sufficient to repay collection. To pro mote the flow, the bruised bark is charred some 5-6 days later by the application of bundles of burn ing wood, and after about another week, the charred bark either falls or is torn off, and the exuda tion begins in earnest. The wounds are then staunched by means of raga or cotton-wool, which absorbs the balsam ; these, after a few days saturation, are collected sod boiled in water. The ter part of the balsam is thus freed from them, and collects beneath the water, hut the rags also undergo a rude wringing iu a kind of rope bag, by which some further balaam reeovered from them, and added to the first. The contents of the boiler cool during the night, and next day the water is decanted, and the balsam is put up in tecomates (gourds) or other vessels for the market. The balsam thus prepared is locally known as de trapo. A small quantity of inferior grade is pro duced, according to Wyss, by bOiling the bark in water ; this is termed de cascaro or tacuasonte. Tbe operation of collecting continues till May ; it is suspended during the rains, but carried on more or less in the dog-days (15 July-15 August). The beating and staunching are only performed on four days of each week, giving 1 cosechas (harvests) a month. In the 2nd year, recourse is had to the patches left untouched from the first year. The bark renews itself in about two years, and it is thus possible to obtain an annual yield of about 2 lb. from the same tree for some 30 years, after which, if allowed 5-6 years' respite, it will again produce.
The balsam is a treacly liquid, of black colour in bulk, but deep orange-brown and transparent in a thin layer ; its odour is balsamic and smoky, but fragrant and pleasant when developed by warming. Its sp. gr. is 1.15-1 .16. Years of exposure to the air do not effect any change in it. It is only very slightly soluble in water, dilute alcohol, benzol, ether, and essential and fatty oils, and not at all in petroleum-spirit, but mixes readily with absolute alcohol, glacial acetic acid, acetone, and chloroform. The balsam contains about 32-38 per cent. of resin, the renaainder being almost entirely cinnameine (0.11„02). An adulterated article is said to be largely pre pai ed in Bremen. The balsam is mostly shipped at Acajutla, in San Salvador, about 40 miles from the Guatemalan frontier. The export in 1855 was stated at 22,804 lb., value 19,827 dollars (of 4s.); in 1876, the value was given as 78,189 dol. The London market value of the drug is about 7s. 6d. a lb. Its chief use is medicinal (see Drugs, p. 819) ; it is also employed in scenting soap.
The tree has been introduced into Ceylon, where it flourishes luxuriantly, but the balsam does nut seem to have yet come into commerce from that island.
Besides tolu, which is the subject of a separate article (see p. 1684), there are several allied bal samic products demanding some notice. (1) The first that may be mentioned is the so-called " white" or " virgin " balsam, the balsamo blanco or catolico, or balsamito, a soft resin secreted in the large ducts of the fruit of the species just described, and extracted by expression. It is highly valued and scarce, and never sent into the market. (2) Much more important commercially is the fragrant balsamic resin collected from Myroxylon peruiferum, a largo tree found in Tropical America, from S. Mexico to Peru, and even as far south as the Brazilian province of Rio Janeiro. It prefers moist mountain valleys, up to 600 feet. The balsam extracted from the wood might, in the opinion of Theodor Peckolt, be conveniently substituted for the officinal balsam, especially as it mixes readily with castor-oil in all proportions. The exudation can be absorbed by cotton-wool, much in the same way as Peru balsam. In the fruit-pods, surrounding the seed, is found a small quantity of pale-yellowish aromatic oleo-resin, which is carefully preserved and highly prized under the name of anguay do guaiani or balsam° do espirito scMto ; it rarely enters commerce. (3) A balsam is obtaiued from in cisions in the stem of the oleo pardo or cabure-iba (Myrocarpus fastigiatus).
Phormiura.—Almost every portion of the plant Phormium tenax (see Fibrous Substances pp. 986-93), but especially the bases of the leaves, is replete with a gum which gives great trouble in the processes for extracting the fibre of the plant. The utilization of the gum deserves more attention than it has yet received, as it ffirms a mucilage capable of replacing that of gum arabic for most purposes.
Piney.—The copalline resins known as " white dammar," " piney resin," or "piney varnish " of S. India and Ceylon, and by some authors (e. g. Wiesner) termed " Manilla copal," are produced by two species of Vateria : V. indica of the W. Peninsula, from Canara to Travancore ; and V. acuminata, common in the hotter part of Ceylon up to 2000 ft. The resin is obtained either by making incisions in the bark of the trees, and allowing it to exude and concrete ; or by making excavations into the tree, where the liquid resin inay collect. Sometimes masses of the hardened resin are found on splitting open old trees. When recently exuded, the resin is quite soft (then termed " varnish "), but it soon hardens into a brittle mass, varying in colour from bright-green to deep-amber, usually translucent, sometimes containing many air-bubbles. It is more soluble in alcohol than black dammar (see p. 1614); it dissolves readily in chloroform, and might serve the purposes of photo graphers' varnish ; it has an advantage over copal in being quite soluble in turpentine and drying oils without preliminary fusion ; its solution in turpentine is turbid, but the addition of powdered charcoal, and subsequent filtering, renders it transparent and colourless, and the solution mixes readily with the drying oils. The sp. gr. of the resin is about 1.121.