ANALYSIS OF THE ROOT OF RHEUM AUSTRALE. 287 
stance, the vegetable substance was considerably swelled, and 
its appearance became gelatinous. When the liquors had been 
strained, which required considerable time, on account of the 
viscidity of the magma, I united the whole and evaporated 
with care; during the operation there was separated a brown 
pulverulent substance, hardly soluble in water, which, sepa- 
rated by the filter and dried, weighed 5 grammes; and which 
when examined, was found to contain tannin; this I believe 
to be what Hornemann has named apotheme de tannin. 
jipothema of tannin, (oxygenized extractive). The clear 
liquor was concentrated at 100° upon a disk, to an almost dry 
extract, and as friable as possible; this extract was acid; sub- 
mitted to alcohol at 35°, it separated into two portions; one of 
them which was flocculose, contained some traces of apothema, 
and of supermalate of lime, together with a mucilagenous 
substance which has been called gum; this combination 
weighed 1.6 grammes; the other soluble in the alcohol, con- 
tained a little tannin, and probably gallic acid, besides a bitter 
nauseous brown matter, which being as much dried as practi- 
cable, weighed 14 grammes; this is what has been designated 
by the names caphopicrite, and rhabarbarine, a complex 
product, as has been supposed by M. Caventou ; in it exists 
rheine associated with one or more substances. To isolate 
that colouring part of the resin which constitutes this kind of 
combination, I have treated it several times over with an alka- 
line solution. The menstruum at first became reddish purple, 
and threw down a dirty brown flocculent deposit, soluble 
almost entirely in boiling alcohol, but the amount of it was 
exceedingly small. I may state moreover, that when the alka- 
line liquids are not too weak, the mixture produces an entire 
solution. 
Sugar} I believe that there also exist traces of sugar in 
rhubarb, for the part which contains the caphopicrite, exhibited 
upon admixture with yeast, the appearance of fermentation. 
3. I submitted to the action of boiling water, the root ex- 
hausted by the preceding operations, while it was still soft; the 
liquor when filtered had little colour; it evinced, when tested 
