377 
tion was carried out in the Pharmacy Research Laboratory, with 
the following results :— 
The sample consisted of about 150 grammes of the bark and 
a tin containing about 17 grammes of the powder. The bark 
was in pieces about 5 to 10 centimetres long, 3 centimetres wide, 
and 2 to 38 millimetres thick. Externally the younger pieces 
exhibit alternating longitudinal bands of dark grey and paler 
grey thin cork; in the older pieces greyish warts occur which 
eventually become very numerous. ‘The inner surface is pale 
grey. The transverse section is pale yellow grey, and shows 
under the lens a thin dark cork and numerous whitish secondary 
medullary rays. No odour; taste at first slight, slowly followed 
a persistent acridity. Under the microscope the bark is 
characterised by the abundance. of sclerenchymatous cells and of 
calcium oxalate, the latter being in prismatic or in cluster crys- 
tals. The medullary rays are one or two cells wide, and most of 
the cells contain a cluster crystal of calcium oxalate. In section 
the sclerenchymatous cells differ but little in size or shape from 
the parenchymatous cells; they are arranged in irregular masses 
throughout the secondary bast. Not unfrequently the cavity 
of the cell is filled with a prismatic or cluster crystal of oxalate. 
Associated with the sclerenchymatous cells are bast fibres, singly 
or in groups; they are strongly thickened and distinctly striated. 
In the parenchymatous cells oil globules occur, and also a few 
minute starch grains. A longitudinal section, stained with 
phloroglucin and hydrochloric acid, exhibits elongated cells 
filled with a yellowish, granular secretion; the inner. lamella of 
the walls of the cells is suberised and lignified. These characters 
agree with those of Croton barks. : 
The powder accompanying the sample of bark was examined, 
and found to be derived from the bark. 
ion. 
principle ether a further small quantity, and chloroform none. 
t is therefore not volatile in steam. 
Cc 
= 
