RHEUM UNDULATUM. ORD. XL. .Holeracezx. 85 
From the above calculation, we may readily estimate the profitable re- 
turn to the cultivator of a rhubarb crop—fine specimens of English Rhubarb 
fetching from five to six shillings per pound. We are informed that the 
London market is chiefly supplied from Banbiary. English rhubarb is 
equally purgative as the foreign, but less astringent and tonic. 
Chemical Properties, §c. Boiling water dissolves about 40 per cent. of 
Turkey Rhubarb, the infusion is limpid, of a deep yellow or orange colour, 
changing to a greenish black with sulphate of iron, and yields a scanty pre- 
cipitate with lime-water, solution of acetate of lead, and oxymuriate of mer- 
cury. Spirit of wine takes up 27 per cent. ; the solution is of a golden yel- 
low, not altered by adding water, but changing to dark olive green by sul- 
phate of iron. Ether dissolves 15 per cent.; the tincture is of a gold yellow 
colour, and on evaporation, leaves a yellow resin. East India Rhubarb is 
bitterer to the taste than that from Turkey, its grain is more compact and 
smooth, and when powdered, it is of a deeper colour. Water dissolves 50 
per cent.; the infusion is thick, and affords more precipitate, on adding a 
solution of isinglass, than that of Turkey Rhubarb; it also yields a copious 
precipitate with lime-water, solutions of corrosive sublimate, or sugar 0 
lead.* Alcohol takes up 40 per cent.; the solution is clear, of a brownish 
yellow, is rendered slightly turbid by the addition of water, and yields a co- 
pious dark green precipitate with sulphate of iron. Ether dissolves only 2 
per cent. . By digesting the remains of the infusion in muriatic acid, and 
afterwards adding spirit of sal-ammoniac, oxalate of lime is precipitated. 
Turkey Rhubarb yields about 48,3 per cent., and East India 30, of this 
oxalate. 
The following constituents were obtained from one hundred parts of fine 
Turkey Rhubarb :— 
Resin : = ‘ i : oo aes 
Gum ; : 31,0 
Extract, tei, ind pallic acta d : 26,0 
Phosphate of lime . : ; 2,0 
Malate of lime . : ; ; 2 6,5 
Woody fibre 16,3 
Water ‘ ‘ 8,2 
* Grey’s Elements. 
