86 ORD. XL. Holeracex. RHEUM UNDULATUM. 
It is generally supposed that Rhubarb contains some oxalate of lime ;— 
Mr. Brande, however, has never succeeded in obtaining oxalic acid from it, 
but he has obtained an uncrystallizable acid, having the characters of the 
malic acid. M.de Lassaignes, however, imagines, that the acid termed 
rheumic by Mr. John Henderson,* is the oxalic acid. 
The following tables, by Dr. Anthony Todd Thomson, show the effects of 
various re-agents on the aqueous infusions of the two varieties of rhnubarb.— 
* Annals of Philosophy. 
