500 
THE TROPICAL AGRICULTURIST. [January 2, 188S. 
attach a high value to the mortars and pestles made 
from this stoue, and " kilbuths," or stone vessels used 
by the native', are prepared from it. It was anxious 
to procure a pestle and mortar, but there were 
difficulties in the way. The proprietor of the quarry 
resides at Mysore, and when an order is placed with 
him he s;nds for the stone, and it is brought back 
to be worked. As he never keeps anything in stock 
he cannot be credited with an enterprising character. 
I next visited Mysore, the city of palaces and dirt, 
but have little to report from here. The Acacia 
Arabica or " Kari Jali," the mulberry, Fieux ladica, 
and a species of alve were growing in the suburbs, 
while Androcctijle A siatica, Hemidesmus Indicus, Rubia 
cordifoliit, and Euphorbia pilulifera, all having great 
virtues, grow as wee Is among the grass. The E. piluli- 
fera is allied to the E. Drummondii of Australia, and 
may be found to have the same constituent, viz., an 
"alkaloid " possessing the properties of calcium oxalate. 
The following are some of the exported articles from 
the districts of Tumkur, Kolar, Kadur, Shimoga :— 
Gall-nuts, gum, honey, kamala (kapile rang), orris 
root, areca-nuts, marking-nuts tamarinds, tobacco, tur- 
meric, cotton, lac, poppy-seeds, coconuts, oils and oil 
seeds, cummin, fenugreek, capsicum, sugar, coriander, 
mustard, coffee, ginger, safflower, and cardamoms. 
Such produce as honey, gum, certain fruits and seeds 
are gathered by a wild race called " Karumbas," living 
in the jungles on the south and west of the province. 
The produce of the country is exporte I by way of 
Mercara, to Mangalore on the western coast, or from 
Mysore aud Bangalore by rail to Madras and other 
stations on the Madras and South Indian railways. 
I was unable to visit the gold mines in Kolar, the 
iron-works in the north, the Astragram sugar refinery 
(now a distillary), and the tanneries and dye factories, 
in which a chemist could take delight. But these 
must be left for other pens to describe. If I have the 
fortune on another occasion to draw a month's privilege 
leave, I hope to go to tome other part of India, where, 
if it be as interesting as Mysore, I may be induced 
to notice other resources of our vast "Empire in the 
East." — Chemist and Druyyist. 
CHEMICAL NOTES ON TEA. 
UY DR. B. II. PAUL AND A. J. COWXLEY. 
So far as the chemistry of tea has bejn studied its 
most important constituents appear to be an essen- 
tial oil to which the aroma is due, theine, legumin, 
and an astringent substance analogous to tannin. 
"With the exception of theine, however, little is 
known of the chemical characters and relations of 
thrse constituents or of the mode in which the 
quality of tea is influenced by them. For instauce, 
what is commonly spoken of as the " strength " of 
tea is a tolerably vague quality in itself, and no 
relation has yet been ascertained to exist between 
it and the amount of any particular constituent. Con- 
sidering the physiological properties of theine it 
might be supposed that the " strength " of tea de- 
pends to a considerable extent upon the amouut of 
this f-ubstance, and some probability is given to that 
opinion by the great variation in the published state- 
ments as to the proportions that have been obtained 
from different kinds of tea. According to the earlier 
determinations by Mulder, Chinese and Java tea 
were represented to contain less than 1 per cent, 
of theine. Subsequently, Stenhouse found from 1 to 
2 per cent, in a number of samples examined by 
hiin, while Poligot obtained from 2-5 to 4, aud in 
oi e case as much as 5 84 per cent, of theine. On 
examining the methods by which these results were 
obtained they all appear to be open to suspicion 
of inadequacy to meet on the one hand the diffi- 
culty of obtaining theine in a sufficiently pure condition, 
and on the other hand that of extracting the whole 
of it in such a condition. 
The method of sublimation by which Stenhouse* 
sought to determine the amount of theine in tea is 
not capable of furnishing correct results, since the 
'* 1'hU. May.\*x\\\. (1813;, 427. ' 
greater part of the theine is decomposed, and thi« 
circumstance will account for the low results ob- 
tained by him. Peligot's method * of treating an 
aqueous infusion with basic lead acetate, aud eva- 
porating the filtrate after separating excess of lead, 
was equally unsuitable for the determination of theine, 
since its extraction by water is incomplete, and while 
the quantity thus obtained cannot ba rendered pure 
by crystallization without loss, there is also a risk 
of obtaining too high a result if the product is not 
sufficiently purified before weighing. Consequently 
the data of both these experimenters cannot be re- 
lied upon for accuracy, and the results of some 
preliminary experiments furnished us with evidence 
that a further investigation of the subject was desir- 
able. Even Zoller's f more recent examination of a 
sample of tea from the Himalayas, in which he 
found 4-94 per cent, of theine, does not sufficiently 
remove uneertainty as to the amount of theine in 
average tea, for his memoir suggests that the tea 
examined by him was of exceptional quality. More- 
over, his method of extracting the theine by thoroughly 
disintegrating the leaves with strong sulphuric acid 
does not appear well adapted for the purpose. Liebig 
was of opinion that theobromine was also obtained 
from the Himalaya tea examined by Zoller, though 
this point was not settled conclusively, since the 
quantity of material was too small for the purpose. 
In two other samples Zoller was unable to find any 
trace of theobromine. In our analyses of tea we have 
always endeavoured to trace the presence of theo- 
bromine, but so far we have in every instance ob- 
tained only negative results. It must, however, be 
mentioned that as the quantity of tea operated 
upon for the determination of theine is but small, 
a minute proportion of theobromine might in that 
case escape detection, and we, therefore, propose to 
operate upon large quantities to decide this point. 
In the course of an inquiry undertaken for the 
purpose of ascertaining the circumstances that deter- 
mine the differences of il strength " in tea, one of 
the points to which we directed our attention 
was the extraction of the theine in such a way, 
that precise analytical results could be obtained, 
admitting of a comparison of different kinds of tea 
in regard to the percentage of theine. After several 
trials we found that the method we had previously 
adopted for coffee]: was capable of furnishing satis- 
factory results, and that with careful manipulation 
the amount of theine in tea could thus be deter- 
mined with considerable accuracy. 
For this purpose 5 grams of powdered tea is 
moistened with hot water, well mixed with 1 gram 
of hydrate of lima, and the whole dried on a water- 
bath. The dry residue is then transferred to a small 
percolating apparatus an:l extracted with strong al- 
cohol. The clear liquor is to be evaporated to re- 
move alcohol, and the remaining water solution, 
measuring about 50 c. c, mixed with a few drops 
of dilute sulphuric acid, which separates a trace of 
lime and partially decolourizes the liquid. After 
filtering the slightly acid solution, it is transferred 
to a separator and well shaken with chloroform, 
which gradually abstracts the theine- This part of 
the operatiou requires particular care, for though 
theine is freely soluble in chloroform it is necessary 
to shake the acidified water solutiou with several 
successive quantities of chloroform in order to re- 
move the whole of the theine. Unless the quantity 
of theine is very large, about 200 c. c. of chloro- 
form will be sufficient for 5 grams of tea, and that 
should be used in 5 or 6 separate portions, testing 
the last portions by distilling off the chloroform 
in a weighed flask until it is found that there is 
no more theine taken up. The whole of the chloro- 
form solution is then to be placsd in a stoppered 
separator and shaken with a very dilute solution of 
caustic soda. This will remove a small quantity of 
colouring matter and render the theine solution 
* Ann. Chim. Vhy.t., [3], xi., 138. 
t Ann. Chem. Pharm., clvii., 185. 
J Pharm, Juurn y [3], xvii., 921 
