204 LEGUMINOS^. 



is plentifully scattered throughout the Montana around Plato and other 

 small ports on the right bank of the Magdalena. He states that he 

 saw at least 1,500 lb. of the drug on its way for exportation. From 

 another source, we know that it is largely collected in the valley of the 

 Sinu, and in the forests lying between that river and Cauca. None is 

 collected in Venezuela. 



Description — Balsam of Tolu freshly imported is a light brown, 

 slow-flowing resin, soft enough to be impressible with the finger, but 

 viscid on the surface.^ By keeping, it gradually hardens so as to be 

 brittle in cold weather, but it is easily softened by the warmth of the 

 hand. Thin layers show it to be quite transparent and of a yellowish 

 brown hue. It has a very agreeable and delicate odour, suggestive of 

 benzoin or vanilla, especially perceptible when the resin is warmed, or 

 when its solution in spirit is allowed to evaporate on paper. Its taste 

 is slightly aromatic with a barely ])erceptible acidity, though its 

 alcoholic solution decidedly reddens litmus. 



In very old specimens, such as those which during the last century 

 reached Europe in little calabashes ■-' of the size and shape of an 

 orange, the balsam is brittle and pulverulent, and exhibits when broken 

 a sparkling, crystalline surface. This old balsam is of a fine deep 

 amber tint and superior fragrance. 



When Balsam of Tolu is pressed between two warmed plates of glass 

 so as to obtain it in a thin even layer, and then examined with a lens, 

 it exhibits an abundance of crystals of cinnamic acid. Balsam of Tolu 

 dissolves easily and completely in glacial acetic acid, acetone, alcohol, 

 chloroform or solution of caustic potash ; it is less soluble in ether, 

 scarcely at all in volatile oils, and not in benzol or bisulphide of carbon. 

 The solution in acetone is devoid of rotatory power in polarized light. 



Chemical Composition — The balsam consists partly of an 

 amorphous resin, not soluble in bisulphide of carbon, which is supposed 

 to be the same as the dark resin precipitated by the bisulphide from 

 balsam of Peru. Scharling (1856) assigned the formula C^^H'^O^ to that 

 part of the balsam which is soluble in potash. 



If Tolu balsam is boiled with water, it yields to it cinnamic and 

 benzoic acid, which we have (1877) perfectly succeeded in separating by- 

 repeated recrystallization from water ; we have before us good speci- 

 mens of either, showing not only different melting points (133° C. and 

 121° C), but as to our crystals of benzoic acid, isolated from the balsam 

 as stated above, we find that they also do not evolve bitter almond oil 

 Avhen mixed with sulphuric acid and chromate of potassium. The acids 

 may also be removed by boiling bisulphide of carbon. 



Busse ^ showed that benzylic ethers of both benzoic and cinnamic 

 acid are also constituents of the balsam, the cinnamate of benzyl being 

 present in larger quantity. 



Upon distilling the balsam with water, it affords 1 per cent, of 

 Tolene, CR'', boiling at about 170° C. _ This liquid rapidly absorbs 

 oxygen from the air. Bj^ destructive distillation, the balsam affords the 



1 I have seen it imported very fluid into - The gourds, " Kiirbsen," of the list of 



London by way of New York. — Sept. Basle of 1647. 



1878 F A F ^ Berichte der Deiifschen Chemiicheu Ge&- 



selhchaft, 1876. 833. 



