444 CONVOLVULACE^. 



Mechoacan ; and on the other hand, the paler mechoacan was in later 

 times known as White Jalap. 



Mechoacan root is now known to consist (at least in part) of the large 

 thick tuber of Ipomwa Jalapa Pursh (Batatas Jalapa Choisy), a plant 

 of the Southern United States and Mexico. As a drug it has been long 

 obsolete in Europe, having given place to jalap, which is a more active 

 and efficient purgative. 



The botanical source of jalap was not definitely asccertained until 

 about the year 1829, when Dr. Coxe of Philadelphia published a 

 description and coloured figure, taken from living plants sent to him 

 two years previously from Mexico.^ 



Manner of Growth — Though we have cultivated the jalap plant 

 for many years, we have had no opportunity of examining the seedling, 

 but judging from analogy suppose that it has at first a small tap-root 

 which gradually thickens after the manner of a radish. A root of jalap, 

 called by some tuber and by others tuhercule, throws out in addition to 

 aerial stems, slender, prostrate, underground shoots which emit roots at 

 intervals. These roots while but an inch or two long become thickened 

 and carrot-shaped, gradually enlarging into napiform tuber-like bodies, 

 which emit a few rootlets from their surface and taper off" below in long, 

 slender ramifications. The thickened roots have no trace of leaf-orsfans ; 

 the aerial stems grows from the shoot from which they originated. 



Fresh jalap roots (tubers) are externally rough and dark brown, 

 internally white and fleshy. 



Collection — Jalap is said to be dug up in Mexico during the whole 

 year.^ The smaller roots are dried entire; the larger are cut transversely, 

 or are gashed so that they may dry more easily. As drying by sun-heat 

 would be almost impracticable owing to the wetness of the climate, the 

 roots are placed in a net, and suspended over the almost constantly 

 burning hearth of the Indian's hut, where they gradually dry, and at the 

 same time often contract a smoky smell. Much of the jalap that has of 

 late arrived has been more freely sliced than usiial, and has obviously 

 been dried with less difficulty. 



According to Schiede, whose account was written in 1829,'* the Indians 

 of Chiconquiaco were at that period commencing the cultivation of jalap 

 in their gardens. 



Description — The jalap of commerce consifjts of irregular, ovoid 

 roots, varying from the size of an egg to that of a hazel-nut, but occa- 

 sionally as large as a man's fist. They are usually pointed at the lower 

 end, deeply wrinkled, contorted and furrowed, and of a dark-brown hue, 

 dotted over with numerous little, elongated, lighter coloured scars, 

 running transversely. The large roots are incised lengthwise, or cut 

 into halves or quarters, but the smaller are usually entire. Some of 

 the small roots are spindle-shaped or cylindrical; others can be found 

 which are nearly globular, smooth and pitchy-looking, but these latter 

 are seldom solid. Good jalap is ponderous, tough, hard and often horny, 

 becoming brittle when long kept, and breaking with a resinous non- 



^ Armrkan Journal of Med. Science.% v. when the aerial stems have died down. 



(1820) 300. pi. 1-2. ^ Linmea, iii. (1830)47.3; Pharm. Journ. 



- It is plain that such a proceeding is viii. (1867) 652.— We are not aware of any 



irrational. The roots should be dug up more recent account. 



