332 Scientific Intelligence. 
leaving ‘60 per cent. of cinchonine, which crystallised freely, and also ‘30 
or ‘40 loss chiefly in water of the hydrated alkaloids. This result must 
be considered extremely favourable. 
I have noticed the product of some fine quills of South American red 
bark as 3°60 per cent.,* the larger bark of the same parcel producing 
3°91 of alkaloid. Dr Riegel obtained from 1 oz. red bark, of best quality, 
4:16 per cent. by Rabourdin’s process, or 3°90 by that of Buckner. Of 
this 2°65 per cent., soluble in ether, was reckoned as quinine, and the rest 
was set down as cinchonine.}+ I have obtained a much higher per-centage 
of alkaloid from large and peculiarly fine ‘‘ red bark,”’ but I see no reason 
to doubt that even this higher per-centage would be attained in the East 
Indies, if time were allowed for the growth. 
The exact period at which it would be advisable to cut the bark must 
be ascertained by experiment, but I think this should take place as soon 
as the bark attains to a thickness which would repay the cultivation. 
There would be positive disadvantage in allowing the bark to attain such 
an age as is indicated by many of the specimens from South America, if 
the object to be attained is the extraction of the alkaloids; since there is 
a continual process of deterioration of these after a certain period of the 
history of the bark, which is connected with the oxidation of the red 
colouring matter, and the production, in very old trees, of those fine de- 
scriptions of bright red bark which command, indeed, a high price in the 
market (as much at the present time as eight shillings per pound), but 
which would not, in many cases, be more valuable for the production of 
quinine than bark of one year’s growth. 
I next examined the younger-bark of one year’s growth, taking care 
to select the most mature portion, and found that it yielded 2:59 of alka- 
loid, of which 2°55 (soluble in ether) appeared to be quinine and cincho- 
nidine, and in part crystallised into tolerably white sulphate, which showed 
perhaps arather larger proportion of cinchonidine than in the older bark. 
On the other hand, the proportion of cinchonine seemed notably less, viz., 
only 0-04 per cent., but it is possible that the separation was not exactly 
effected between the cinchonine and cinchonidine, which is not easily 
accomplished by ether in such small portions. 
The above result induced me to pay further attention to the leaves, 
concerning which the absence of any carmine sublimate by heat led me at 
first to an unfavourable conclusion. The decoctions and infusions made 
by Mr M‘Ivor, though in perfectly good condition, showed that the con- 
tents changed most rapidly under the influence of the oxygen of the 
atmosphere as soon as ammonia was added to the, at first, decidedly acid 
liquor. Fortunately, a good supply of several ounces of dried leaves had 
been sent over, and from these I succeeded in obtaining quinine,$ though 
in very small quantity, but presenting its usual characteristics, dissolving 
in acids and precipitated by alkalies as a whitish hydrate, soluble in ether, 
and left by this on evaporation as a resinons-looking body, having the 
usual bitter taste, also crystallising not only as a sulphate, but as an 
oxalate of quinine (the latter being the more critical test), but nevertheless, 
presenting a characteristic implication with resinous or extractive matter 
such as is usually met with in the very smallest quills or canutillos of 
#* « T)lustrations of Nueva Quinologia,” under head C. succirubra, p. 15. 
+ “ Pharm. Central-blat,” for July 1852. 
t Described in my “ Illustrations of Nueva Quinologia,” under head C. 
succirubra, p. 14. 
z [This had been previously done by Dr T. Anderson, Superintendent of 
the Botanic Garden, Calcutta.—Kp. Phil. Jour.) 
