S8 

 SOUECE OF THE DRUG CALLED TRAGACANTH. 



The real origin of many of our officinal drugs is involved 

 in obscurity, or the statements made by authors concerning 

 them are in great need of confirmation, even when true. 

 The common gum called Tragacanth, brought to us from the 

 Levant, is no exception. Linnaeus evidently considered it to 

 be produced by the plant he called Astragalus Tragacantha, 

 a French species, called by the Botanists of that country A. 

 massiliensis ; but DeCandolle assures us that no gum what- 

 ever is furnished by that plant. Another species, the A. 

 creticuSf has been named as the source of the drug, and it 

 does appear that a small quantity is obtained from that spe- 

 cies in Candia ; but certainly not the bulk of the samples of 

 commerce. Labillardiere relates that his A. gummifer fur- 

 nishes Tragacanth on Mount Lebanon ; but the samples 

 obtained from thence are said to be not the same as those of 

 commerce, being white and more transparent, and dissolving 

 less readily in water. Finally, Olivier assures us that the 

 principal part of the Tragacanth used in Europe comes from 

 Astragalus verus, a Persian species. The only certain con- 

 clusion that can be drawn from these statements is, that Tra- 

 gacanth is a secretion from some sort o^ Astragalus belonging 

 to that curious division of the genus which consists of spiny 

 bushes. 



The subject has been very recently investigated by James 

 Brant, Esq., H. M. consul at Erzeroum, who has sent ex- 

 cellent dried specimens of the Tragacanth plants of Koor- 

 distan to the Hon. W. F. Strangways, who has placed them 

 in my hands. One of these is labelled " The shrub that 

 yields the white or best variety of Gum Tragacanth," and is 

 the A. gimimifcr, a very pretty bush, unknown in the gardens 

 of Europe, and very much to be desired as an ornamental 

 plant. For it is covered with myriads of short spikes of 

 yellow flowers embedded in wool, and surrounded by bright 

 green smooth leaves. The specimen before me is little more 

 than a span across, and it has from 70 to 80 of such spikes. 

 Mr. Brant's other Tragacanth is labelled " Shrub from which 

 the red or inferior species of Gum Tragacanth is produced." 

 This is quite a different plant, with hoary spiny leaves, and 

 little cone-like heads of flowers, whose feathery calyxes are as 

 long as the corollas. It is evidently very near the A. micro- 



