203 LEGUMINOSiE. 



a few years of rest he occasionally allowed. Clay or earth is sometimes 

 smeared over the bare wood. 



The trees sometimes exude spontaneously a greenish gum-resin of 

 slightly bitter taste, but totally devoid of balsamic odour. It has been 

 analyzed by Attfield (see opposite page). 



Secretion of the Balsam — No observations have yet been made 



as 



by the operation of scorching the bark. Neither the unscorclied bark 

 nor the wood, as we have received them, possess any aromatic odour. 



The old accounts speak of a very fragrant resin, far more valuable 

 than the ordinary balsam, obtained by incisions. We have made many 

 inquiries for it, "but without the least success. Such a resin is easily 

 obtainable from the trunk of 31. Toluifera. 



Description— Balsam of Peru is a liquid having the appearance of 

 molasses, but rather less viscid. In bulk it appears black, but wbeu 

 examined in a thin layer, it is seen to be of a deep orange brown and 

 perfectly transparent. It has a balsamic, rather smoky odour, whicb is 

 fragrant and agreeable when the liquid is smeared on paper and warmed, 

 It does not much affect the palate, but leaves a disagreeable burnmg 

 sensation in the fauces. 



_ The balsam has a sp. gr. of 115 to 116. It may be exposed to the 

 air for years without undergoing alteration or depositing crystals. It is 

 not soluble in water, but yields to it a little cinnamic and traces ot 

 benzoic acid ; from G to 8 parts of crystallized carbonate of sodmm are 

 required to neutralize 100 parts of the balsam. It is but partiall} 

 and to a small extent dissolved by dilute alcohol, benzol, ether or 

 essential or fatty oils, not at all by petroleum-ether. The balsam 

 mixes readily with glacial acetic acid, anhydrous acetone, absolute 

 alcohol or chloroform. Its rotatory power is very insignificant. 



Chemical Composition— The peculiar process by which balsam o 

 Peru IS obtained, causes it to contain a variety of substances not toun 



^" '^- - '—' - ' • '■ r« ; hence the two drugs, 



:d. possess very different 



properties. 



most 



ToluU 



of 



1^ ^m V-^X^t^* £ 



Three parts of the balsam mix readily with one part of bisu]i)hide o 

 carbon, yet a further addition of the latter will cause the separation oi. 

 brown flocculent resin. If the balsam be mixed with thrice its wei,' ^ 

 of bisulphide, a coherent mass of dark resin, sometimes amountm 

 about 38 per cent, of the balsam, is precipitated. The bisulphide 

 carbon forms then a perfectly transparent brown liquid. If tins sp utio 

 IS shaken with water, the latter removes Cinnamic and Benzoic acias. ^^^ 

 separate them, ammonia is cautiously added, yet not in excess. 

 solution of cinnamatc and benzoate thus obtained and duly concentra ' 

 yields botli these acids in white crystals on addition of acetic or n} u 



chloric acid. 



above stateJ, 



. 1 le resm separated by means of bisulphide of carbon as above bu ^^ 

 is a black brittle amorphous mass, having no longer the specific oaou 

 the balsam. It is soluble in caustic alkalis, also in alcohol ; the solutio 



forms 



By saturating tlie acid aqueous liquid . 



vpl wT'''"''' '^ ''''"™'^" ^ transient bright from which the cinnamcin again 

 jei.ow' hue ; an excess of ammonia trans- but imperfectly. 



