CULTIVATION OF JALAP. 



345 





3. The frequent admixture of other roots with the jalap of 1867. 

 commerce. 



The cultivation of jalap to be successful must result in pro- Essential 

 ducing the drug identical in medicinal activity with that hither- re< l uisltes - 

 to employed, of uniform good quality, of moderate price, and in 

 sufficient quantity to be noticeable in the market. Experience 

 alone can determine whether all or only some of these desider- 

 ata can be attained. 



Let us now consider what is the climate, and what the soil, of 

 the region in which the jalap-plant (Exogonium purga, Benth.) 

 naturally thrives ; and what the method actually pursued for 

 collecting and preparing the drug for the market. On these sub- 

 jects the most graphic information that I have met with, is con- 

 tained in a letter addressed by Dr. Schiede, a German traveller and Dr. Schiede. 

 botanist, to Dr. D. F. L. von Schlechtendal ; it bears date Mexico, 

 26th October, 1829, and was published in the periodical called 

 Linncea the following year. Of this letter, the following is a 

 translation : 



Before I leave Chiconquiaco 1 I must communicate to you the 

 most interesting facts which I have observed on the occurrence 

 of Convolvulus Jalapa, as well as what I have learnt respecting 

 the collection of the root and its preparation for the market. 

 In my last collections from Jalapa, I sent you a large number of 

 flowering specimens, and added a short description of the plant, 

 so that this latter I may here omit. 



The herbaceous plant whose tuberous root furnishes the 

 almost indispensable medicine called jalap, does not grow in the Jalap, 

 immediate vicinity of Jalapa, but several thousand feet higher 

 on the eastern slopes of the Mexican Andes, especially about 

 Chiconquiaco and the neighbouring villages, and also, as I hear, 

 about San Salvador, on the eastern slope of the Cofre de Perote. 

 The mean altitude at which the plant occurs may be stated as 

 about 6000 feet. In this region it rains almost the whole year 

 through. During summer tine clear mornings are commonly 

 succeeded by violent showers in the afternoon ; in winter indeed 

 these latter do not occur, but dense mists lie for days and weeks 

 with but few clear intervals, on the mountains as well as on 



1 Chiconquiaco is a village situated on the mountain known as the Cofre 

 de Perote, and in the region called by the Mexicans Tierrafria. D.H. 



