448 CONVOLVULACEiE. 



SEMEN KALADANiE. 



Semen Pharbitidis; Kaladana. 



Botanical Origin — Pponuea NW^ Roth (Pharhitis Nil Choisy, 

 Convolvulus Nil L.), a twining annual plant, with a large blue corolla, 

 much resembling the Major Convolvulus (Pharhitis hispida Choisy) of 

 English gardens, but having three-lobecl leaves.^ It is found throughout 

 the tropical regions of both hemispheres, and is common in India, 

 ascending the mountains to a height of 5000 feet. 



History — The seeds of this plant were employed in medicine by the 

 Arabian physicians under the name Habbun-nil ; and they have pro- 

 bably been long in use among the natives of Hindustan. In recent 

 times they^ have been recommended by O'Shaughnessy, Kirkpatrick, 

 Bidie, Waring^ and many other European practitioners in India as 

 a safe and efficient cathartic. 



Description — The shape of the seeds is that which would result if 

 a nearly spherical body were divided perpendicularly around its axis 

 into 6 or 8 almost equal segments, only that the back is less regularly 

 vaulted. The seeds are I of an inch high and nearly as much broad ; 

 100 of them weigh on an average about 6 grammes. There is a smaller 

 variety imported from Calcutta, of which 100 seeds weigh but little over 

 3 grammes ; in every other respect the two sorts are identical. Both 

 are of a dull black, excepting at the umbilicus, which is brown and 

 somewhat hairy. The adjacent parts of the thin shell (testa) crack in 

 various directions, if the seed is kept for a short time in cold water. If 

 it is removed from the upper part of the vaulted back, the radicle be- 

 comes visible, surrounded by the undulated folds of the cotyledons, 

 which join perpendicularly, but cannot be easily unfolded by reason of 

 the thin seminal integument. Cut transversely, the cotyledons show 

 the same curled structure. Throughout their tissue, small bright 

 glands in considerable number are observable, even without a lens. 

 The kernel, which is devoid of albumen, has at first a nutty taste, with 

 subsequently a disagreeable persistent acridity. When bruised in a 

 mortar, the seeds evolve a heavy earthy smell. 



Microscopic Structure — The seed is covered with a dark blackish 

 cuticle, formed of a densely packed tissue, the cells of which show 

 zigzag outlines. The dark brown epidermis is composed of very close 

 cylindrical cells, about 70 mkm. in length and 5 to 7 mkm. in diameter ; 

 they require to be treated with chromic acid in order that their structure 

 may be distinctly seen. 



The tissue of the kernels is made up of thick- walled cells. Between 

 this tissue and the shell there is a colourless layer, about 70 mkm. 

 thick, of thin-walled corky parenchyme. The cotyledons contain in 

 their narrow tissue numerous granules -of albuminous matter, mucilage, 

 a little tannic acid, crystals of oxalate of calcium, and a few starch 

 granules. The glands or hollows, before alluded to as occurring through- 



^ In Hindustani Nil signifies blue, and ^ Yig. in Bentley and Trimen, Med. 



Kala-dana, black seed. Plants, part 22 (1877). 



3 Pharm. Journ. vii. (1866) 496. 



