2 
ME. J. BEOUGHTON’S CHEMICAL AND PHYSIOLOGICAL 
other constituents remain unaffected. Chemically these alkaloids greatly resemble each 
other, their solutions both rotate the plane of polarization to the left, and their salts 
and behaviour with reagents are very similar. With the exception that cinchonidine 
will crystallize readily from alcohol, and produces no green colour with chlorine and 
ammonia, their reactions differ in degree only*. The circumstances under which they 
mutually occur in living cinchona-barks, taken in connexion with their chemical proper- 
ties, would lead me to class the alkaloids in two groups : 1st. Quinine, Cinchonidine, 
Quinidine ; 2nd. Cinchonine. I have never yet met with the alkaloid aricine in any 
Indian cinchona-bark, though it has frequently been looked for. 
Quinovin is a very constant constituent of all the parts of a cinchona-plant, as is also 
quinic acid ; the latter is the acid of cinchona, as tartaric acid is that of the grape, and 
is found in the free state in most of the juices. The peculiar red substance known as 
cinchona-red, though found in all dried bark, does not exist in the living plant, and is 
formed by the action of the free oxygen upon the peculiar tannin : hence a slice of 
fresh bark always becomes brownish red when the internal tissues are exposed. 
On account of their being the most vigorous, the oldest, and in suitable climates the 
hardiest trees, I have generally chosen the plants of C. succirubra for the subjects of 
experiment in cases where a special treatment of the plant was necessary. The bark 
of this kind is very rich in alkaloids and the cinchona tannin : it may contain all the 
alkaloids, though quinidine is rarely found ; the other three invariably occur. It has 
a great tendency to produce cinchonidine. I have every reason for believing that the 
natural processes resulting in the formation of the several alkaloids are similar throughout 
the quinine-yielding species though differing in degree. 
Occurrence of Alkaloids in various j 'parts of the Plant. 
The bark is yar excellence the seat of the alkaloids, that of the trunk being the richest. 
I here quote analyses of the trunk-bark of various species growing on the Neilgherries, 
showing the percentages of alkaloids in the dry bark. 
1 . 
2. 
3. 
4. 
5. 
6. | 7. 
A lanceolate- 
species tree, 
name unknown, 
5 years. 
C. officinalis, 
5 years old, 
fine tree. 
C. officinalis, 
5 years old, 
mean tree. 
C. Calisaya, 
years, 
mean tree. 
C. succirubra, 
7 years old, 
mean tree. 
C. peruviana, 
5 years old, 
mean tree. 
C. micrantha, 
4 years old, 
mean tree. 
Total alkaloids 
11-40 
6-76 
4-34 
4-53 
7-43 
6-25 
7-1 
Quinine 
9-75 
1 65 
3 76 
3-00 
2-18 
2-16 
3-27 
1-26 
1-72 
5*71 
0-41 
5-84 
0-3 
6-8 
Cinclionidine and cinchonine 
Crystallized cinchonidine 1 
sulphate obtained j 
Ditto quinine sulphate 
Cinchonine 
0-38 
10-13 
1-94 
3-45 
2-00 
1-60 
0-70 
2-17 
4-92 
1-51 
1-80 
0-00 
3-84 
0-0 
0-0 
6-8 
* Howard (Illustrations to the ‘ ISTuova Qninologia ’ of Pavon) states that the cinchonidine found in G. peru- 
viana is that peculiar cinchonidine described by Wittstein (J. pr. Chem. 72, 101), and generally known as 
