TAXINE. 
425 
§§ 5 i 2 , 513 .] 
pain about the pubes, etc. Pilocarpine, given internally, does not 
alter the size of the pupil, but the sight may, with large doses, be affected. 
This may be due to the presence of pilocarpidine. If a solution is 
applied direct to the eye, then the pupil contracts. No fatal case of 
its administration has occurred in man. The probable dangerous dose 
would be about 130 mgrms. (2 grains) administered subcutaneously. 
Pilocarpine must be classed among the heart poisons. 
Isopitocarpine, 1 C n H 16 N 2 0 2 , is an oily liquid, boiling at 261° at a 
pressure of 10 mm.; [a] D =+42-8°. The following are the melting- 
points of some of the salts of pilocarpine and isopilocarpine :— 
Pilocarpine. 
. 
Isopilocarpine. 
Nitrate .... 
176° 
159° 
Hydrochloride 
204°-205° 
127° 
Hydro bromide 
185° 
147° 
Methiodide .... 
An oil. 
114° 
Pilocarpidine, C 10 H ]4 N 2 O 2 , a crystalline alkaline mass, soluble in 
alcohol and chloroform, and a little soluble in water. The nitrate, 
Ci 0 Hi 4 N 2 O 2 HNO 3 , gives prismatic crystals, melting at 137°, and 
[a] D =+73-2°. The aurichloride melts at 124°-125°. The picrate is 
an oil. Pilocarpidine causes dilation of the pupil. 
X.—Taxine. 
§ 512. Properties of Taxine. —The leaves and berries, and probably 
other portions of the yew tree ( Taxus baccata), are poisonous. The 
poison is alkaloidal, and was first separated by Marme. 
Taxine (C 37 H 52 O 10 N).—Taxine has hitherto been obtained as a snow- 
white amorphous powder, scarcely soluble in water, but dissolving in 
alcohol, in ether, and in chloroform ; insoluble in benzene. It melts 
at 82°, gives an intense purple-red with sulphuric acid, and colours 
Frohde’s reagent reddish-violet. 
A slightly acid aqueous solution of the alkaloid gives precipitates 
with all the group reagents and with picric acid. 
The salts are soluble in water ; the hydrochloride may be obtained 
by passing gaseous HC1 into a solution of the alkaloid in anhydrous 
ether. The platinochloride forms a yellow micro-crystalline powder, 
(C 37 H 52 O 10 N) 2 H 2 PtCl 6 . The salts are generally difficult to crystallise. 2 
§ 513. Poisoning by Yew. —Falck has been able to collect no less 
than 32 cases of poisoning by different parts of the yew—9 were from 
1 Jowett, Journ. Chem. Soc., lxxvii. 473. 
2 A. Hilger and F. Brande, Ber., xxiii. 464-468. 
