ALKALOIDS FROM JAMAICA CHINCHONAS. 101 
In his experiments he followed the formula given by the Edinburgh 
College of Physicians for the preparation of Quinine from Yellow Bark, 
on account of the ease and simplicity of the process. The result was 
that the leaves of C. succiruóra yielded as much as from :75 to 1:00 
per cent. of alkaloids. The characteristic white acicular crystals of 
Quinine deposited on the evaporating glass could be plainly discerned 
by the naked eye, and presented a striking contrast to the larger, flat, 
four-faced, oblique prisms of Chinchonine procured from the residual 
liquor... From a few young leaves of. C. micrantha and C. nitida, Sul- 
phate of Chinchonine, with other amorphous crystalloids, probably 
Chinchonidine or Quinidine, were obtained, but owing to the limited 
quantity of material submitted for analysis, no definite proportions 
could be determined. 
The Red Bark (C. succirubra) is the most valuable of all the Chin- 
chone, as it yields a richer percentage of Quinine and Chinchonine 
than.any other species, not even excepting the famous Yellow Bark (C. 
Calisaya). The young shoots of this species are readily propagated, 
and have proved in Jamaica the most vigorous and hardy, Mr. Wilson 
having found less difficulty in preserving them alive than any of the 
other species. He has planted them in the open spaces between the 
coffee bushes, where they are freely exposed to the influences of fresh 
air, rain, and sunshine, and they have required no special attention 
other than the occasional clearance of weeds. Dr. Daniell attaches 
considerable importance to the relative proportion of the alkaloids in 
this species. His experience of the employment of Chinchonine in- 
stead of Quinine at Sierra Leone showed that it induced vertigo 
and cerebral congestion to such an extent as to compel him to discon- 
tinue its use, and his further observations in Jamaica confirm him in 
this opinion. The toxic or stimulant properties of Chinchonine he 
considers to be equal to those of Quinine, but the therapeutic or cura- 
tive power is. greatly inferior, being, according to his own observations 
in West Africa and Jamaica, in the proportion of 2 to 5, and i in the 
the reports. of the French army surgeons, so low as 3 to 10. 
