TAMPICO JALAP. 
2S3 
in a dry state; but this extractive is not wholly resin, for from it there can he 
easily separated, by means of water, 15 per cent, of saccharine matter, and the 
greater part in the state of grape sugar. This, doubtless, has been Mr. South- 
all’s source of error; he has evidently taken the alcoholic extractive as pure 
resin, whereas the half is nothing more than sugar. This saccharine matter 
exists in the officinal jalap, but in a somewhat different proportion ; four selected 
tubercules (very heavy) gave 20| per cent, of pure dry resin, associated with 
which, in the alcoholic extractive, was 9f per cent, of sugar. The sum of these 
two very nearly coincides with the 30 per cent, of Mr. Southall, as obtained by 
him from the Yera Cruz variety. 
Thinking it likely that resina jalapae was to be met with in an impure state in 
pharmacy, four samples were obtained in town from first-class sources (whole¬ 
sale and retail); these upon examination proved that the suspicion was not 
unfounded. 
No. 1. Resinous. Translucent at edges. Brittle. Made from Yera Cruz. 
9 
11 11 1» U _ 11 
,, 3. . ,, ,, 15 p.c. moisture. ,, 
” 4 * { 15 p. c. sugar. \ Very °P a< l ue - 7 P- c - moisture. Tampico. 
This substitution of Tampico for Yera Cruz jalap has doubtless been caused 
by the praise lately bestowed upon the former. 
I cannot agree with Mr. Southall that both jalaps and their respective resins 
are equally active, inasmuch as the resin in Tampico jalap is present invariably 
in much smaller quantity, and is chemically different from the true resin of 
jalap, for it is almost wholly soluble in ether, whereas in the other only 12 per 
cent, is dissolved. This soluble portion is known as jalapic acid, the insoluble 
as jalapin* (this test affords a ready means of distinguishing it from other resins, 
such as guaiacum, scammony, etc.). Jalapin is known to the chemist as rhodeo- 
retin, from the rose-red colour produced by the action of oil of vitriol upon it, 
and in this reaction it is resembled by the Tampico resin, which seems similar 
to that obtained from the Ipomoea orizabensis , the male, fusiform, or stalky 
jalap of Guibourt, whose resin from this reaction was named para-rhodeoretin. 
In odour, Tampico jalap much resembles peat fuel,—peat probably is used 
in the drying of the root; this peculiar smell is very'characteristic, it clings to 
it even after it has been dried in a stove for a considerable time ; in its powder 
it is easily recognized, and even its extract and resin retain the odour to a slight 
extent; but it is not impossible that this peculiarity is due to volatile oil, as a 
species of the Order Convolvulacece yields a volatile oil (Rhodoriza). 
Since making the above experiments, Mr. D. Iianbury has kindly lent me a 
paper entitled, “'Elude sur les Convolvulacees Purgatives,” by M. Atnhroise 
Andouard. The author states, that Tampico jalap is that described by the late 
M. Guibourt as “jalap digite majeur analyses of some specimens indicate 5 
per cent., the finest examined yielded 14 per cent. He fully coincides with the 
opinions of Guibourt, who says, that Tampico jalap should not be used in the 
preparation of medicines, in which jalap is a constituent. He (the author) 
does not think that this jalap should be even classed with the false jalaps, such 
as the male or fusiform jalap, or the rose odour jalap. The resin he states is 
purgative, for he himself has tested its efficacy in a few cases ; his opinions are 
also confirmed by other experimenters ; but he considers this jalap as an inferior 
kind. In concluding his essay, M. Andouard says, that the jalaps of pharmacy 
* A large proportion of jalapine used in this country is supplied by the German market—• 
and is nothing more than the decolorized resin of either Tampico or the fusiform or male 
jalap. 
