106 FICOIDER. 
Chemical composition.—The most interesting principles pre- _ 
sent in the seeds are astringent principles which we provision- 
ally call a and 6 Gisekia tannin. « Gisekia tannin is obtained 
by agitating an alcoholic extract of the seeds with ether, it 
forms an orange varnish, in which nodules gradually form on 
standing, which on microscopic examination are seen to consist 
of narrow plates and a few needles of a deep yellow colour. 
The ether extract is easily soluble in alkalies with deep orange 
coloration, and is reprecipitated by acids in yellow flocks. In — 
water the ether extract is nearly wholly soluble with yellow 
colour and astringent taste. Ferric and ferrous salts give a 
dirty deep brown coloration, without any tinge of blue. Potas- 
sium cyanide a deep orange coloration. Both acetates of lead 
chromate deep yellow, slowly changing to yellowish bro 
Bromine water dirty brownish yellow. It reduces an alke 
copper solution on boiling and precipitates gelatine in white 
flocks. 
8 Gisekia tannin occurs as a deep orange powder, and is 
tained by acidulating the aqueous alcoholic extract after agita- 
tion with ether, when the tannin is precipitated. In cold water _ 
it is slightly soluble, but dissolves easily in boiling water 
a yellow coloration, the liquid becoming'turbid on cooling, 
_ is easily soluble in amylicalcohol — Ferric salts afford a n 
black precipitate, without any tinge ofblue. In alkalies it dis- 
solves with ® wine red coloration, the tint being brighter with 
ammonia than with the fixed alkalies. Potassic cyanide gives @ 
similar coloration. * Both acetates of lead afford flesh coloured 
precipitates. Bromine water a yellowish precipitate, sulphate 
of copper whitish. It precipitates gelatine in white flocks, a 
reduces slightly an alkaline copper solution on boiling. 
- ‘We failed to detect any al 
The anthelmintic properties of 
to these tannin-like principles. 
kaloidal principle in the see 
the seeds are very probably 
