May i, 1889.J : THE TROPICAL AGRICULTURIST. 
7?i 
CHEMICAL NOTES ON COCA.* 
As the value of coca leaves outside of South 
America depends almost entirely on the amount of 
cocaiue yielded by them, it has been considered de- 
sirable to furnish such chemical information as bears 
directly upon the cultivation of the coca plant in 
various parts of the Colonies and India. In the 
preparation of this information we are indebted to 
Mr. Alfred G. Howard, F. 0. S., F. L. S., grandson 
of the late Mr. John Bliott Howard, F. R. S._, the 
well-known authority on cinchona. By the aid of 
correspondents in the West Indies, Ceylon, India and 
Java, numerous samples of coca leaves grown in 
those countries were obtained with full particulars 
as regards the circumstances under which the plants 
were cultivated and the methods adopted in drying 
the leaves. These leaves were carefully analysed by 
Analyses of 
Mr. Howard, and the results are of a very in- 
teresting character. They point out not only the 
best plants to grow, but also the circumstances best 
suited to produce a high percentage of alkaloids, and 
the best methods for gathering and curing the leaves. 
It is important to point out that the percentages 
of alkaloids often quoted in regard to coca leaves 
cannot be compared with one another, owing to 
different methods pursued in dealing with them. Mr. 
Howard states that the alkaloid determined in all 
his analyses "is simply cocaine in a pure state which 
is split up into crystallizable and uncrystallizable 
cocaine as nearly as could be done when working 
with such small quantities." 
The following analysis of coca leaves, for con- 
venience of reference, have been divided into four 
series: — 
Leaves of Coca. 
Localities, 
A. — Ceylon 
British Guiana 
B. — Java 
C— Jamaica 
St. Lucia 
D. — India 
Per cent. 
Crystal- 
lizable. 
0-60 
0-60 
0-47 
0-22 
030 
0-34 
0-24 
033 
0-24 
0-25 
0-20 
0-22 
0-45 
0-27 
0-23 
0-30 
041 
Per cent. 
Uncrystal- 
lizable. 
0-00 
000 
0-00 
033 
0-09 
0-09 
0'08 
0-43 
0T6 
0-33 
0-45 
0-33 
0-35 
0-23 
0-20 
0-23 
0-17 
Total 
Cocaine. 
0-60 
0'60 
0-47 
0-55 
0-39 
0-43 
032 
0-76 
0-40 
0'58 
0-65 
0-55 
080 
0-50 
0-43 
0-53 
0-58 
Elevation. 
Feet. 
2300 
1500 
1500 
Sea-level 
820 
3000 
5000 
100 
100 
600 
600 
Sea-level 
900 
2200 
2200 
Remarks. 
Dried in the sun. 
Dried in the shade \ Grown at Botanic 
Dried in the sun \ Gardens, Peradeniya. 
Dried in the shade. 
Grown at Buitenzorg. 
„ „ Sockaboemi. 
Dried in the sun. 
t-. . , . , , 1 1 "1 Plants 6 months old : 
Dried m the shade t grown afc gpring 
" " sun J Gardens Estate. 
t-> -~a :„ 11. f Plants 5-6 years old : 
Dried in the sun ! 1. « • n ; i 
< grown at Oastleton 
" " " (. Gardens. 
Dried in the shade. 
Darjeeling. 
Bogracote. 
Alipore : dried in shade 10 days. 
Ranchi, Ohota, Nagpore. 
„ „ ,, dried in shade, 
then rolled and fermented like tea- 
In the 'Annual Report of the Botanic Gardens,' 
Ceylon, for the year 1887, Dr. Trimen, F.R.S-, 
states that the coca plants at Peradeniya, and possibly 
all the plants now in the colony, have been derived 
from a Kew plant received in 1870. As there has 
been only one coca at Kew, such plants would 
necessarily belong to the variety novo-c/ranatense already 
described. The specimens of leaves received from Dr. 
Trimen for analysis with his letter of February 27, 
1888, appear, however, to belong to the typical Peru 
plant. They are in some cases 3i inches long and 
1J inch wide ; the are oval-pointed, dark green, and 
correspond very nearly with specimens collected in 
Peru by Mr. Pearce. The analyses of the Ceylon 
leaves show exceptional richness in crystallizable coca- 
ine ; they have no uncrystallizable cocaine and the 
total yield is the highest, with two exceptions, of 
any received. Of the two specimens grown at the 
Botanic Gardens, Peradeniya, it will be noticed that 
the leaves dried in the shade yield '60 per cent, of 
cocaine, while the same leaves dried in the sun 
yield only "47 per cent. Leaves grown in Ceylon at 
1,500 feet and 3,000 feet respectively show the same 
results. The difference of elevation has apparently 
not produced any effects on the yield in cocaine. 
The leaves received from British Guiana are not 
distinguishable in general characters from the Ceylon 
leaves. They are perhaps less coriaceous, but have 
the same dark green colour on the upper surface 
and are quite as large. The yield of cocaine is some- 
what less, but while in the Ceylon leaves there is 
no uncrystallizable cocaine, in the British Guiana leaves 
the amount is "33 per cent. If it should be proved 
that this is a highland plant it would not be likely 
* From the Kew ' Bulletin of Miscellaneous Informa- 
tion,' January, 1889. 
97 
to be so productive in alkaloids at sea-level in the 
tropics. 
The Java leaves represent cocoa grown at 800 feet, 
3,000 feet, and 5,000 feet respectively. They belong 
to the intermediate forms provisionally classed as 
Bolivian with narrowly oblong leaves, pointed, dark 
green above and glaucous beneath. They contain 
chiefly crystallizable cocaine, the result of the most 
favourable sample yielding "34 per cent, crystalliz- 
able cocaine and '09 per cent, uncrystallizable cocaine. 
The leaves grown at an elevation of 5,000 feet 
show a less favourable result than those grown at 
either S00 feet or 3,000 feet. This may be owing in 
part at least to the fact that they were dried in 
the sun. Mr. Howard states that the Bolivian leaves 
which usually reach this country from South America 
contain - 40 per cent, of crystallizable cocaine and 
•05 of uncrystallizable. 
The plants grown at Jamaica and St. Lucia are 
characteristic of the variety novo-grdnatense. They 
are all apparently derived from the Kew plant. The 
leaves are obviate, blunt, or emarginate, and mem- 
braneous, and of a light grassy green colour when 
dry. In one instance the total yield in cocaine is 
exceptionally high. This occurs in leaves forwarded 
by the Hon. W. B. Bspuet grown at Spring Garden 
Estate. The larger proportion of the cocaine is, 
however, uncrystallizable. These leaves were from 
plants only six months old grown at nearly sea-level 
and dried in the shade. The same leaves dried in 
the sun appear to have lost - 36 per cent, of cocaine. 
Leaves grown at the Oastleton Gardens at an ele- 
vatiou of 600 feet, in perhaps less rich soil, yield 
•65 per cent, of cocaine, of which -45 per cent, is 
uncrystallizable. A good series of such leaves were 
obtained from Mr. W. Fawcett, F. L. S. There is 
apparently a considerable difference in the yield of 
