330 SHEFFIELD ASSOCIATION OF CHEMISTS AND DRUGGISTS. 
kind known as Tampico jalap. The source of this variety is not accurately known, nor 
is there much authentic information as to its exact place of growth. As met with in 
the market it is of very varying quality, the finer specimens resembling, in great measure, 
the tubers of the rose- scented jalap in their general external aspect, but internally they 
are soft, spongy, and dark-coloured, and more or less decayed with a tarry odour. 
Much diversity of opinion obtains in regard to the medicinal value of this variety, 
some averring it to be a good and proper substitute for the Vera Cruz variety, while 
others sirongly condemn the substitution. 
The Vera Cruz, or officinal jalap, yielded, to Mr. Evans’s experience in the laboratory, 
an average of 38 per cent, of extract, prepared according to the Pharmacopoeia directions 
from good average samples of the drug,—the maximum yield being 42 per cent., and 
the minimum 35 per cent. 
Tampico jalap, on the other hand, yielded very uncertain results and the extract ob¬ 
tained differed greatly in its constitution from that obtained from the true officinal 
drug. 
A careful analysis of these extracts gave the following results:— 
Extract from officinal jalap yielding 40 per cent, of B. P. extract gave,— 
Resin insoluble in ether.15*2 per cent. 
Resin soluble in ether.0-0 „ 
Grape sugar soluble in alcohol . . . 9’0 „ 
The extract from Tampico jalap similarly treated, gave,— 
Resin soluble in ether.7*0 per cent. 
Resin insoluble in ether.6*0 „ 
Grape sugar soluble in alcohol . . .26-9 „ 
Thus, though the percentage yield of alcoholic extractive is greater in the Tampico 
than in the Vera Cruz, its resinous contents are very inferior, and its percentage of resin 
resembling true Jalapce resina is very low indeed. In this respect the Tampico much 
resembles the rose-scented jalap, according to the late Professor Guibourt’s analysis, viz.:— 
Resin.323 
Molasses soluble in alcohol . . 16 47 
From the above data there can be little room for doubt that Tampico jalap cannot be 
substituted for the officinal. The large imports, nevertheless, prove that it is becoming 
extensively used as a substitute for the more costly variety, and although the small 
yield of resin may cause its use to be abandoned in the laboratory, it is yet possible it 
may be used in the mill, and either as an entire substitute or partial one for the Vera 
Cruz variety. It is, therefore, a desideratum to have some readily available test where¬ 
by the sophistication may be detected ; and the analytical results here noted would 
appear sufficiently suggestive of such a test. 
The lecture was illustrated by specimens from the museum of the Association. 
Mr. Sharp referred to the difference between the product yielded by the same plant 
in different climates, and thought that the plant which yielded the Tampico jalap might 
be the same as that which furnished the Vera Cruz, but grown in a colder part of the 
country. 
Mr. Sumner considered that the great differences in the quality of the true jalap arose 
from the tubers not being always gathered at the right time. He alluded to the dis¬ 
turbed state of Mexico, as interfering with the proper collection of the drug, and pro¬ 
tested against the Tampico jalap being substituted for tbe Vera Cruz. 
After further discussion, Mr. Robinson proposed and Mr. Shaw seconded a vote of 
thanks to Mr. Evans, which was carried by acclamation. 
SHEFFIELD ASSOCIATION OF CHEMISTS AND DRUGGISTS. 
This Association held their monthly meeting at the Cutlers’ Hall on Wednesday night, 
the 11th of December; on which occasion A. H. Allen, Esq., F.C.S., gave an important 
and highly interesting lecture on “ Diffusion,” which the lecturer said was not generally 
understood, but he would explain the meaning of this word in connection with chemis- 
