304 
THE TROPICAL AGRICULTURIST. [November i, 1887. 
sea as ever were caught," or in other words, there are 
probably as rich mines yet waiting for discovery in 
Brazil as ever were worked. I believe the time will 
yet come for a gold rush to Brazil, that will lead 
eventually to its being peopled and developed as 
California, Australia, and Southern Africa have been. 
In this necessarily compressed review of matters, 
Brazilian, I have not been able to enter so fully or so 
clearly into a explanation of the purport of what I 
had to say, but I will conclude by stating that I do 
strongly and emphatically believe in a great and pros- 
perous future career of this vast empire of 3,207,800 
square miles Troubles may come, but troubles will go, 
and Brazil will nourish for — well, a very long time. — 
Chamber of Commerce Journal. 
TEA ANALYSES: VARYING RESULTS. 
We draw attention to Mr. Cochran s interest- 
ing letter, further explaining the results of his 
recent analyses of green tea leaves. The conclusion 
forced on us is, that it would be of importance 
that planters should have before them the results 
of analyses of teas grown at varying elevations, 
and, above all, that such analyses should be spread 
over each season and every month of the year. 
For it is now obvious that not only do the con- 
stituents of tea differ according to soil and ele- 
vation, but that they are most extensively affected 
by the meteorological conditions of season. We 
believe we are correct in saying that in proportion 
to the percentages present of theine and potash, 
so is the value of well manufactured tea, and 
Kellner's analyses have proved conclusively that, 
while those constituents are most abundant in 
warm, genial summer weather, they are reduced to ex- 
ceedingly minute proportions by the cold of winter. 
The experiments having been made in Northern 
India, where the extremes of summer heat and 
winter cold are much more marked than in 
Ceylon, it is, of course, probable that the con- 
trasts between the results of analyses in May and 
November, may not present such violent differences 
in Ceylon as was the case in India. But there 
can be no doubt, that similar variations will be 
here shown, for we know without the aid of 
ehemistry, by the tests of the London market, 
that our teas gathered in cold, droughty, windy 
weather have sold at lower prices and evoked very 
different opinions amongst brokers, than those 
gathered and manufactured in warm, mildly moist 
conditions of the atmosphere. The scientific con- 
elusions resulting from such analyses as those of 
Kellner, the results of which Mr. Cochran placed 
before us in Ceylon, and those which Mr. Cochran 
himself has made or may make, possess a purely 
technical interest of no small value. But we need 
scarcely point out to intelligent planting readers 
the importance of the results in a practical and 
cultivator's point of view. There seems no reason 
why careful pruning and other treatment of tea 
plants should not be successful in inducing the 
heaviest possible yields of leaf in those months 
which have been proved by scientific and practical 
tests to give the largest proportions to the veget- 
ation of theine, potash and phosphoric acid, on 
which the economic and commercial value of the 
tea leaf so largely depend. Mr. Cochran feeling 
certain of the correctness of his process for as- 
certaining the proportion of theine (the crystals 
of which are very beautiful, largely resembling 
those of quinine), it is obvious that further an- 
alyses are required to settle the question whether 
the Torwood proportion is normal or, from certain 
causes, exceptional. Indeed, there is no reason 
why, if Mr. Cochran's attention were specially 
directed to the matter, the result of a series of 
analyses might not be to enable planters so to 
modify the processes of withering and fermenting 
as to retain in the dried leaf a larger poroentage 
than is at present done, of the theine and potash, 
which are evidently in large proportion in the green 
leaf, and which perhaps (?) may be carbonized in 
the great heat of the roasting process. 
♦ 
MR. COCHRAN ON THE ANALYSIS OF 
GREEN TEA LEAVES. 
Colombo, 4th October 1887. 
Dbak Sir, — I shall be glad if you will allow 
me to refer to your remarks of 28th September 
on my analyses of green tea leaf. First, as regards 
the drying operations, — these were necessary, in 
order that the leaves might be reduced to a fine 
state of division, suitable for the application of 
solvents. To avoid as far as possible chemical 
change being produced in the leaves, the drying 
was conducted at a temperature below 160* F. except 
in the case of sample No. 4, during the drying 
ef which the temperature for some time was con- 
siderably above this limit. The powdered and sifted 
product had a fine olive green colour. I think any 
methad of treating the leaves which did not involve a 
preliminary drying operation would be impracticable. 
Again, as to the amount of theine formed in 
Torwood estate tea leaves, I do not wonder that 
you were surprised. No one could have been 
more surprised tlian I was myself at the result 
of this determination, nevertheless I have con- 
fidence in the results obtained. The theine, as 
reported, was obtained in a state so nearly pure, 
that when a weighed quantity was placed in a 
watch-glass covered by another inverted and well 
fitting watch-glass, and placed on the sand, bath 
over a small flame, from 93 to 95 per cent of the 
theine placed on the lower glass was recovered in 
the upper glass as a sublimate of pure crystallized 
theine. Moreover, when the alkaloid was dissolved 
in various menstrua, and crystallized on the slide 
of the microscope, it yielded the aggregations of 
clear, colourless, sharply definedneedle-shaped crystals 
characteristic of the genuine article. After all, 
though the percentage of theine was uncommonly 
high, it was not unprecedentedly so ; thus Peligot 
obtained in different teas the following amounts 
of theine— 2-7, 3-5, 4-1 and even 6-21 per cent. The 
process followed by me was the same as that used 
t»y O. Kellner, who appears to be the only chemist 
who has recorded systematic analyses of green tea 
leaf during different months. He made twelve 
analyses during six months from May to November, 
and found the percentage of theine to vary from 
2-85 by a gradual decrease to 1 per cent. I am 
not aware whether the tea upon which he experi- 
mented, was high-grown or low-grown. 
In the Melbourne assays quoted by you, "mineral 
ash" is necessarily lower than my " total ash" as the 
former means total ash minus carbonic acid. In 
the Melbourne assays, also, the term soluble salts 
does not quite answer to my " soluble ash." 
The latter is the portion of total ash that is 
soluble in water, the former is the ash obtained by 
evaporating to dryness the aqueous extract, and 
igniting the solid residue. Hence soluble salts 
are sometimes reported as " ash of aqueous extract." 
The potash in the total ash of Torwood estate 
tea, plucked in the middle of April, agrees very 
closely with that found by Kellner in tea plucked 
in the end of May. In the beginning of May, 
Kellner found nearly three times as much potash 
as was present at the end of November, his figures 
calculated upon "pure ash," i. e., ash without 
carbonic acid", being May 15th, 49-06 per cent, Nov- 
ember 30th, 17-31 per cent. M. COCHRAN. 
P. S. — I send you a sample of the theine, obtained 
from the green leaves of Torwood est ate tea, crys- 
tallized from water on the elide of a miscroscope. 
M.C. 
