BOTANICAL AND PHARMACEUTICAL DESIDERATA. 153 
Libanus have never been correctly traced to the plants 
which yield them, nor has Tournefort's relation of the for- 
mation of this substance in the bark been confirmed. It is 
still more important to ascertain if the tragacanth of Eze- 
room is brought into British commerce, and whether it is 
yielded by the Astragalus strobiliferus. 
Senna.— -The source of the East Indian or Mocha senna. 
Is it really the foliage of Cassia lanceolala ? 
Catechu. — To observe the processes by which the various 
kinds of Catechu, Cutch> Terra Japonica, and Gambir are 
obtained ; and if from trees, whether from others besides 
Acacia Catechu, Areca Catechu, and Uncaria Gambir. 
We want to identify the trees with the respective extracts. 
Cubebs. — Does Piper Cubeba ox Piper Caninum in Java 
yield cubebs ? If both, which gives the best ? 
Cassia. — Botanical specimens of the plants seen to yield 
Cassia bark in Kwagse, China, Malabar, Egypt (and 
Brazil.) 
Cassia-buds of the grocers'-shops. — To procure speci- 
mens of the bark in Cochin China, and Japan, and flowering 
specimens for the Herbarium. 
Rhubarb. — The true source of the medicinal rhubarb, 
and especially of the Batavian Rhubarb. Strange to say, 
we are still in the dark respecting the real origin of this 
most valuable drug ! In this and all such cases the drug 
should be procured by one who is an eye-witness to its being 
gathered, and specimens of the foliage and fruit should ac- 
company it, and be carefully dried for the Herbarium on 
the spot. 
Arrow-root. — The sources of the East Indian arrow-root. 
It is made largely at Travancore. 
Salep. — The different plants which yield salep in Asia 
Minor, Persia, and especially the best kinds. 
Aloes. — The true sources of the Soccotrine, Clear, Bom- 
bay, Hepatic, East Indian, and Mocha aloes. 
Minia Batta or Stone Oil, from Borneo. — Whence is 
this solid oil or fat obtained ? Is it abundant or rare ? 
