346 CULTIVATION OF JALAP. 



1867. their declivities. The plant prefers shade, and is found only in 

 woods where it climbs over trees and bushes. The flowers ap- 

 pear 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 is to say in March and 

 April. The tubers are sometimes elongated, sometimes round, 

 and always terminate in a rootlet, In the fresh state they are 

 whitish, almost inodorous and full of a viscid juice which has a 

 peculiar acrid taste. When collected, the large tubers are cut 

 Drying the through, but the smaller left entire. As drying them in the sun 



tubers. would probably be impracticable, they are placed in a net and 

 then hung over the al most-con stantly burning hearth where by 

 degrees they dry, and by which process they almost always ac- 

 quire a smoky appearance and somewhat sooty smell. In about 

 ten to fourteen days the Purgob 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 

 Garden culti- the jalap plant in their gardens. The future will show whether 



vation of jt. s p 0wers are i n any degree impaired by cultivation. Culti- 

 vation will afford the advantage that the roots may be collected 

 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 oiir gardens on 

 a large scale ; is not the potato 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 will 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 Chi- 

 conquiaco, perhaps in the Sierra Madre. 



To this account may be added a few lines extracted from a 

 letter received from a valued correspondent of my own in 

 Mexico, to whom I am also indebted for more than a hundred 

 living tubers of the jalap plant : 



" The tubers of jalap require a deep rich vegetable soil (dJbris 

 of the leaves of Finns, Quercus, Alnus, etc.), and as they grow 

 at an elevation of from 7000 to 10,000 feet above the level of 

 the ocean, they can stand a good deal of cold and even frost 



