At least eight varieties of senna leaf are known in commerce in Europe—1. the Senna palthe; 2. Senna of Sennaar or Alexandria; 3. of Tripoli; 4. of Aleppo; 5. of Moka; 6. of Senegambia; 7. the false or Arghel; 8. the Tinnevelly.
In Egypt the senna harvest takes place twice annually, in April and September; the stalks are cut off with the leaves, dried before the sun, and then packed with date leaves. At Boulka, the drug is sorted, mixed, and adulterated, and passed into commerce through Alexandria.
Alexandrian senna, according to Mr. Jacob Bell ("Pharmaceutical Journal," vol. 2, p. 63), contains a mixture of two or more species of true senna. It consists principally of Cassia obovata and C. obtusata, and according to some authorities it occasionally contains C. acutifolia. This mixture is unimportant, but the Cynanchum Arghel, which generally constitutes a fifth of the weight on an average, possesses properties differing in some respects from true senna, and which render it particularly objectionable. The Tinnevelly senna, that most esteemed by the profession, is known by the size of the leaflets, which are much larger than those of any other variety; they are also less brittle, thinner and larger, and are generally found in a very perfect state, while the other varieties, especially the Alexandrian, are more or less broken. The leaves of the Cynanchum are similar in form to those of the lanceolate senna, but they are thicker and stiffer, the veins are scarcely visible, they are not oblique at the base, their surface is rugose, and the color grey or greenish drab; their taste is bitter and disagreeable, and they are often spotted with a yellow, intensely bitter gummo-resinous incrustation. Being less fragile than the leaflets of the true senna, they are more often found entire, and are very easily distinguishable from the varieties which constitute true Alexandrian senna.
In their botanical character they are essentially different, being distinct leaves, not leaflets, which is the case with true senna.
The SUMBUL root, which has recently been introduced into the French market, is the root of an umbelliferous plant, which is characterised by a strong odor of musk. The pilgrims, on their return from Mecca, generally import to Salonika, Constantinople, &c., among other articles of trade, various plants with a musk-like odor. The preparation of these vegetable substances is said to be effected by smearing them over with musk-balsam.
FOOTNOTES:
[1] Ure's Dictionary of Arts and Manufactures.
[2] Fractional parts are not necessary to include.
[3] Dr. Lindley is in error as to the discriminating duties—British cacao pays 9s., and foreign 18s.
[4] According to Breen's History of St. Lucia up to 1844.