48 LEAVES 



The student should carefully observe 



(a) The curled and twisted appearance of the dried leaves, 



(b) The angle made by the lateral veins with the midrib, 



(c) The occasional presence of the remains of the flower and fruit, 



(d) The characteristic odour, and, 



(e) After soaking in water, the sinuate-dentate outline (unless 



the leaves are too much broken) ; 



and should compare them with 



(i) Belladonna leaves (see p. 43), 

 (ii) Henbane leaves (see p. 49), 

 (iii) Foxglove leaves (see p. 53). 



Constituents. Stramonium leaves contain the same alkaloids as 

 belladonna leaves, but in somewhat smaller proportion, the average 

 of commercial samples being about 0'22 per cent. ; the percentage 

 may, however, rise to 0*4 or exceptionally to 0'7 per cent. ; South 

 African leaves 0*54 per cent., Egyptian 0*35 per cent (hyoscyamine 

 only). Daturine was the name given to the mixture of alkaloids 

 originally extracted from the drug. 



The alkaloids in the leaf are localised chiefly in the epidermis, particularly 

 the upper, and in the bast parenchyma of the veins, the midrib containing more 

 than the petiole, and both being much richer than the leaf. Hence the practice 

 sometimes followed of rubbing the leaves through a coarse sieve (laminating), 

 and rejecting the midribs and larger veins should be discontinued, especially 

 as thereby the difficulty of identifying the leaves is increased. The main stem 

 contains but little alkaloid, and therefore should not be present in the drug. 



Assay. The drug may be assayed by the process official for belladonna 

 leaves. 



Adulterations. Xanthium strumarium (N.O. Composite) ; short, 

 conical hairs containing cystoliths, uniserial, simple hairs and globular, 

 multicellular, glandular hairs ; no cluster crystals of calcium oxalate. 



Xanthium macrocarpum, de Candolle ; said to possess three forms 

 of hairs, two protective and one glandular, one of the former being 

 short and lignified ; cluster-crystals smaller and less numerous ; 

 transverse section of the midrib shows six bundles (D. Stramonium 

 has only one). 



Carthamus helenioides, Desfontaines ; epidermal cells large, walls 

 straight, cuticle striated ; large, pluricellular protective hairs, small 

 glandular hairs arising from the whole surface of an epidermal cell 

 (hi D. Stramonium from a small spot) ; no cluster-crystals ; well- 

 developed secreting ducts. 



Chenopodium hybridum, Linne ; cluster-crystals abundant ; epi- 

 dermal cells small, walls nearly straight ; occasional hairs with slender 

 pedicel and large, bladdery, water-storing terminal cell. 



