January 2, 1888.] THE TROPICAL AGRICULTURIST. 501 
quito colourless, so that on distilling off tho chloro- 
form from a weighed flask the theine remains in 
a oondition fit for weighing. When the operation 
is carefully carried out the theine will be per- 
fectly white. In this way we have been able to 
obtain results of great uniformity. 
Our first experiments were made with Indian and 
Cingalese tea, the general result showing that both 
kinds contained a much higher percentage of theine 
than has hitherto been generally supposed, and that 
the variation in the amount of this substance was 
not considerable. In this respect, however, there 
seems to be a marked difference between tea and 
coffee ; the amount of theine in tea is by no means 
a constant quantity, and so far as the tea of India 
and Ceylon is ooncerued, >* varies from 322 to 4'60 
per cent. This is taking Hie tea in the ordinary 
air dry condition in which it met with in com- 
merce. The following table gives the results of our 
determinations in twenty-eight samples that were 
Beloctod for this purpose as representing a wide 
range of quality, as may be understood from the 
fact that tho prices realised by the corresponding 
parcels in public sale varied from Id. to 3j. per 
pound. The sample No. 10 was tea of exceptionally 
fine quality, that was valued at 64. or It. per 
pouud, and the sample No. 4 consisted of the hairs 
detached from the learos in siftiug:— 
Theioe per 
Approxi- 
ceut. 
mate 
.'loistur© 
elevation 
I't?r cent* 
Ori- 
of place 
ginal 
Dry 
of growth. 
tea. 
tea. 
Ctylon Tea. Ft. 
I. 
Penhros 2600 
88 
4 - 89 
2. 
V.h.O — 
6-0 
1 oo 
4 oo 
3. 
Nahalma 300 
56 
4 04 
480 
4. 
Hairs from tea leaves — 
60 
2-40 
2-57 
5. 
Hardenhuish l'ekoe 3500 
3'8 
408 
4 2 t 
0. 
AVoodstock Pekoe 
Souchong 4200 
36 
3-44 
3-57 
7. 
Rndella Broken 
Pekoe 4800 
46 
1-10 
430 
8. 
Morton l'ekoe ... 400 
y. 
l'enhros Broken 
4-2 
3 98 
4-15 
Pekoe 2500 
64 
4-64 
4-98 
10. 
Strathollie Orange 
Pekoe 2000 
5-4 
4-10 
433 
n. 
Nahalma Orange 
Pekoe ., 300 
5-4 
4-06 
4-29 
12. 
Veuturo Orange 
Pekoe 4800 
5-4 
3-74 
3-95 
14. 
St. Leys Pekoe Dust 4600 
5-6 
346 
3 66 
14. 
Venture Pekoe Sou- 
chong 4300 
4-3 
3-40 
3 57 
15. 
Venture Broken 
Orango Pekoe ... 4300 
66 
393 
4-26 
16. 
Calsay Pekoe Sou- 
chong 5000 
6-2 
322 
343 
17. 
Venture Pekoe ... 4300 
5-6 
8-48 
368 
18. 
St. Clair Orange 
Pekoe 4200 
4-6 
3-90 
409 
/» Han Tea. 
19. 
I'okoe Hps, picked out — 
1 'Token l'ekoe ... — 
7 56 
427 
4 62 
20. 
70o 
4-48 
4-81 
21. 
l'ekoe — 
6 40 
4 16 
4-44 
22 
Orango l'ekoe ... — 
4 HO 
406 
4-89 
•is! 
l'okoo — 
5 CO 
4-48 
4-74 
24. 
Broken l'okoo ... — 
4 80 
3 76 
3-95 
26. 
Pokoo — 
510 
3 66 
386 
26. 
"Weak" tea ... — 
6-80 
4-i >a 
4 35 
27. 
"Strong" tea ... — 
580 
4-18 
4 43 
2s. 
Mixture — 
0-00 
3 61 
3*7 
At present wo have not had an opportunity of 
UMoJnlng many samplos of Chinese or Java tea 
that oou d bo accepted as authentic, but so far as 
wo have boon able to judge the amount of theine 
is lots than in tho tea of India and Ceylon. We 
Intend, however, to continue the inquiry in that 
direction as goon as we can obtain suitable samples. 
Bat, so f» r as tho tea of India and Coylou is 
ooqeerued, it is at leant evident from (he dau above 
tfivcu, as compared with the prices uioutioiie I, that 
the marketable value of tea is not to any great ex- 
tent dependant on or proportionate to the amount of 
theine it may contain, however important that con- 
stituent may be iu other respects. Neither cau the 
"strength" of tea, as that term is generally under- 
stood, be taken as proportionate to the amount of 
theine. This is evident from the results of the 
analysis of the two samples, 20 and 27, whioh were 
selected by experienced judges of tea to represent 
extreme cases of difference as to strength. The 
amount of theine in 27 is greater thau in 20, but 
to such a small oxteut that the difference in strength 
of the tea represented by thoso samples could not 
be ascribed to the theine they contain. 
It appears to be much more probable that the 
" strength " of tea is chiefly determined by the 
amount or couditiou of the astringent constituent, 
the precise nature of which is at present only partially 
known. Moreover, when the mode of preparing tea 
is considered it is also probable that this quality 
of "strength" may be largely influenced in degree 
by the manipulation of leaves in the process of 
manufacture, which comprises stages of fermentation 
and heating in the moist state in contact with at- 
mospheric oxygen, both of which are conditions 
likely to induce alteration of material analogus to 
ordinary tannin. But before any definite opinion 
of this point can be offered in place of the general 
probability above suggested, it will be necessary to 
acquire a better knowledge of the chemical nature 
of that constituent of tea leaves which in some 
respects resembles ordinary tannin. 
The commorcial value of tea is at present esti- 
mated by a combined consideration of several factors, 
among which appearauco counts to a considerable 
degree. Iu this respect the size of the leaves, indic- 
ating their age, and likewise the preseuce of what 
is termed "tip," consisting of the unexpanded leaf 
buds, serve as indications by which tea is classed 
partly as Souchong or Pekoe, and partly also as 
varieties of those kinds of tea. In addition there 
is also the process of tasting procured by tea brokers. 
This consists in preparing infusions of the different 
samples, much in the same m inner that tea is com- 
monly used, and then formin? a judgment as to 
tho value of the samples according to the aroma, 
flavour and other characteri-tics of the correspond- 
ing infusions. This is an art that is practised with a 
surprising degree of precision, so that the results 
arrived at by different operators agree iu a very 
remarkable manner. In carrying out the broker's 
test, tea is infused for five minutes iu boiling 
water in the proportion of about 43 grains to 34 
fluid ounces of water. The infusion is then poured 
off from the leaves iuto a cup and the value of 
the tea estimated by its taste, in this operation the 
soluble constituents of tho leaves are only pui tially 
extracted, aud while more porfect exhaustion of the 
leaves will give about 35 per cent, of extract, the 
amouut takon out in the ordinary broker's method 
of testing doe-i not amouut to more thau 20 per cent, 
on the average. Heuce it is evident that attempts 
to value tea on the basis of tho total amount of 
extract obtainable by treatment with boiling water 
must be entirely fallacious and useless for auy prac- 
tical purpose. Iu respect to tho amouuts of extraot 
thus obtainable from tea of different qualities, there 
is not in reality nny such difference as would afford 
indications of the actual differences iu valuo. Poli- 
got aud others have male determinations of this 
kind, showing that dill. Tent kinds of black tea 
yield from 24 to 47 por cent, of extraot, or 
on tho average 34 to 10 per cent., but those data 
have little practical value. It is indeed uot by tho per- 
fect extraction of tea that its value cau be estimated. 
This must be sought for within the limits of extrac- 
tion which obtain in the or Unary methods of using 
tea, as is tho case in tho broker's method of tcstiug, 
which fairly represents ordiuiry practice iu the use 
of tea, though the infusion is then made strouger than 
it is gen. -rally drunk. 
To obtain some idea of the oxtout to which tho con- 
stituents of tea are oxtractoJ under thoso ordinary 
