EXTRACTS AND ABSTRACTS. 379 
ON THE ORIGIN AND CHARACTERS OF OFFICINAL 
RHUBABB, 
By H. BaiLLoN. 
Linneus was acquainted with five species of Rheum: R. Ribe 
R. rhaponticum, R. compactum, R. palmatum, and R. Rhabarbarum, which 
he named afterwards R. undulatum. Since the year 1762, R. palmatum 
has been generally considered the source of officinal rhubarb. It was, 
that of the Chinese Yam; it is moist, 
and is covered with dark bark. T es are al: 
month (while those of 2. palmatum are completely bleached), and well 
developed, the size of a fan, and resembling the leaves of Ricinus. his 
y proves that the plant producing the true rhubarb was still 
ich i ible enough when the difficulties are considered 
in the way of penetrating into the kin 
‘ers of the Celestial Empire. It was only 
ts of the best Thibetian rhubarb ; a 
condition. One of these was p 
assumed 
times large inflorescences more than 6 feet in height, tapering to a point 
and covered with white flowers, each, with a deeply-hollowed receptacle 
doubled in size by a green grandular disk. The leaves are of large size, 
