161 



REPORT ON TANNIN FROM AN EXUDATION OF 

 PTEROCARPUS DRACO, LINN, AND KNOWN 

 IN JAMAICA AS DRAGON'S BLOOD. 



By Henry Trimble, Ph. M., Professor of Analytical Chemistry in the 

 College of Pharmacy, Philadelphia. 



The origin of this product was described in the Bulletin of the Bo- 

 tanical Department, Jamaica, No 45, July, 1893. As there stated the 

 tree is about 30 feet high, and when an incision is made in the bark 

 drops of red sap ooze out which flow slowly down the bark and gradually 

 harden. 



The sample received by me from Mr. Fawcett was in small garnet- 

 red pieces, transparent at the edges, and breaking with a resinous frac- 

 ture. It much resembled the eucalyptus kino received from Australia. 



On account of its solubility in water, the product closely resembled 

 some other varieties of kino, as well as the one just mentioned from 

 Australia. 



"Warm water dissolved 95.95 per cent of it, the insoluble portion 4.05 

 per cent, consisted chiefly of adhering bark fibre. 



The ash amounted to 2.36 per cent., and was found to consist of po- 

 tassium, calcium, magnesium, and sulphuric, carbonic and phosphoric 

 acids. There were found 34.95 per cent, of tannin and 25 40 per cent, 

 of moisture, which would indicate 46.71 per cent, of tannin in the ab- 

 solutely dry substance. The balance consisted chiefly of gum. A com- 

 plete statement, therefore, might be made as follows : 



Tannin ... 34.85 per cent. 



Moisture 

 Ash 



Insoluble 

 Gum, etc. 



25.40 

 2.36 

 4.05 

 33.34 



100.00 



The tannin was separated from the gums with great difficulty, because 

 of the ready solubility of each in water, and because the tannin caused 

 some of the gum to go into solution in absolute alcohol, and also in a 

 mixture of alcohol and ether. Agitation of the water solution with acetic 

 ether, even in the presence of common salt, did not serve to separate the 

 tannin from the gum, as the latter substance seemed to withhold the 

 former. The close association of the two principles was finally broken 

 up to some extent by agitation of the coarsely powdered sample with 

 sand and acetone. 



Upon allowing the mixture to rest, the gum separated as a jelly-like 

 mass. The acetone solution, when separated and the solvent recovered 

 by distillation, left the tannin in a porous condition, but still admixed 

 with some gum. From this residue the greater part of the still ad- 

 hering gum was separated by treatment with absolute alcohol. 

 The solution was filtered from the gum left undissolved by that solvent 

 and distilled to dryness, and the residue rendered porous by solution in 

 a mixture of alcohol and ether and subsequent rapid vaporisation of 

 those solvents by distillation under reduced pressure. 



