360 



Dr. Wight's Remarks on the culture 



[April 



subject, for, on examining two specimens, one from Bombay, the other 

 from Tinnevelly, the difference was such as to prove, not only the truth 

 of the statement, but the infinite superiority of sun dried leaves. The 

 colour of the Bombay or Egyptian sample was a very pale green, nearly 

 white, the leaves narrow, thick and leathery, or coriaceous, somewhat 

 brittle, and having the smell of well prepared hay. The Tinnevelly 

 one, was of a light pea green colour, very thin, membranous (from 

 excessive luxuriance ?), flexible, and having a sour, vinegar-like smell, 

 as if it had undergone the acetous fermentation while drying. Another 

 indication of the same thing may be found in the great loss of weight 

 the latter sustains in keeping. Again — samples of two sorts of Senna 

 raised in this country from Tinnevelly seed, the one dried in the shade, 

 the other in the sun, were infused in equal quantities of boiling water j 

 the former produced a pale, the latter a deep purplish brown, infusion, 

 corresponding in these respects with infusions of Tinnevelly and Egyp- 

 tian samples. The former is less active, soon decomposes and acquires 

 a sour smell and a muddy opaque colour, while the other retains for 

 many days, under similar circumstances, its transparency, and without 

 undergoing decomposition. These facts, I think, are quite conclusive, 

 and show, in a striking point of view, the advantages of sun drying, 

 considered in relation to medicinal properties only. But that is not all, 

 it is well known that Egyptian Senna is largely adulterated, but is not- 

 withstanding a more efficient medicine than the pure Tinnevelly drug, a 

 difference, which the preceding experiments prove to be, partly at least, 

 attributable to the mode of drying, though other circumstances may 

 contribute to produce this effect. Is the difference altogether attribut- 

 able to the mode of preparation ? or partly to the Egyptian Senna being 

 adulterated with more active ingredients P or to the operation of some 

 other cause yet undiscovered ? 



These are questions of importance, and merit the fullest investigation, 

 both in a medical and commercial point of view. If the comparative 

 inactivity of the Tinnevelly Senna is owing to the first cause, the cure 

 is simple, and the advantages, commercially, very great, since the cost 

 of preparation, both in time and outlay, must be materially lessened 

 by the rapid and unexpensive process of sun drying, as compared with 

 the slow and more costly one of fitting up dark apartments. If it is 

 in any degree owing to the admixture of other kinds of Senn^ leaves, 

 we have an indigenous species to supply them ; and, lastly, if owing 

 to the quality of the soil or culture, the subject still remains for in- 

 vestigation. 



I shall now make some remarks on what I consider the defective 

 points of the Tinnevelly mode of cultivation, and suggest some altera- 

 tions tending to diminish the cost of production, and probably to improve 

 the quality of the produce. 



