65^ 
ON THE CULTIVATION OF JALAP. 
The cultivation of jalap to be successful must result in producing the drug 
identical in medicinal activity with that hitherto 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 de¬ 
siderata can be attained. 
Let us now consider wLat is the climate and what the soil, of the region in 
which the jalap-plant (^Exogoninm Purga^ Benth.) naturally thrives^ —and what 
the method actually pursued for collecting and preparing the drug for the 
market. On these subjects the most graphic information that I have met with, 
is contained in a letter addressed by Dr. Schiede, a German traveller and bo¬ 
tanist to Dr. D. F. L. von Schlechtendal; it bears date Mexico^ 26 October^ 
1829, and vAas published in the periodical called Linnsea the following year. 
Of this letter, the following is a translation : 
Before I leave Chiconquiaco * 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 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 fine clear mornings are commonly suc¬ 
ceeded 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 their declivities. The plant prefers shade and is found 
only in woods where it climbs over trees and bushes. The flower's appear in August 
and September. The root is dug up during the whole year, but probably that is 
preferable which is collected before the young shoots appear,—that ft to say in 
March and April. The tubers are sometimes elongated, sometimes round, and al¬ 
ways terminate in a rootlet. In the fresh state thev are whitish, almost inodorous 
and full of a viscid juice which has a peculiar acrid taste. When collected, the 
larger tubers are cut through, but the smaller left entire. As drying them in the 
sun would probably be impracticable, they are placed in a net and then hung over 
the almost-constantly burning hearth where by degrees they dry, and by which 
process they almost always acquire a smoked appearance and somewhat sooty smell. 
In about ten to fourteen days the Purga is dry, and is then taken by the collectors, 
who are mostly Indians, to Jalapa where it is bought up, and whence it is conveyed 
by way of Vera Cruz into the markets of Europe. 
The Indians of Chiconquiaco are commencing to cultivate the Jalap plant in 
their gardens. The future will show whether its powers are in any degree impaired 
by cultivation. Cultivation will afford the advantage that the roots may be col¬ 
lected at the most favourable time of year, which in the thick forests is attended 
with difficulty. I do not abandon the hope that Convolvulus Jalapa may some day 
be planted in our gardens on a large scale; is not the potatoe a native of a similar 
region? The plant will scarcely bear the severity of a German winter in the open 
air, but the spring and autumn frosts w'ill not, I think injure it, for it has to endure 
the same reduced temperature in its native home. 
I now hear that the root has also been exported from Tampico, which shows that 
it occurs northward of the mountains of Chiconquiaco, perhaps in the Sierra 
Madre. 
* Note. Chiconquiaco is a village situated on the mountain known as the Cofre de Perote, 
and in the region called by the Mexicans Tierra fria. —D. H. 
