ANALYSIS OP THE ROOT OF RHEUM AUSTRALE. .285 
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possessed a sensibly aromatic smell, and a taste, mucilaginous 
at first, then bitter, nauseous and astringent, similar to that of 
common Rhubarb; the saliva was tinged yellow when they 
had been chewed a few moments. 
The roots of which we speak were grated, reduced to small 
fragments and then dried by a stove to reduce them to a state 
of pulverization. This powder when well desiccated had 
nearly the same colour as that of China rhubarb; it was sub- 
mitted to the following analytical treatment: 
Analysis of the root of the indigenous Rheum australe. 
Preliminary experiments. Thirty two grammes were 
treated to exhaustion by hot alcohol, then by tepid w T ater; the 
clear liquids mixed and submitted to slow evaporation, be- 
came more and more turbid, and when reduced to the consis- 
tence of an extract, a brown product was obtained, partly 
soluble in water and weighing 13. 2 grammes. This ex- 
tract, tested by litmus paper, showed evidence of acidity; 
it produced the deepest black with the per-salts of Iron, it 
formed a precipitate with gelatine, and it contained a pretty 
abundant calcarious salt which must be a supermalate of lime. 
The portion not acted upon by alcohol and water contained 
the oxalate of lime, traces of the sulphate and phosphate of 
the same base, a little iron, and lastly lignin and pectin. 
The powder, subjected in a crucible to a moderate heat, soon 
emitted a yellow aromatic vapour, which collected in the 
mouth of a funnel, and attached itself in the form of a yellow 
powder, easily fusible at a high temperature into a kind of 
brown oily liquid. This is the substance which constitutes 
the colouring matter of the rhubarb. 
Analytic experiments. 1. One hundred parts of the pow- 
dered indigenous rhubarb were treated without heat in the 
apparatus for displacement by pure sulphuric ether, until this 
menstruum ceased to become yellow. After the distillation 
of the etherial tincture, continued until three fourths had pas- 
sed over, there remained a deep brownish yellow liquid, which 
