THE TROPICAL AGRICULTURIST. 
[July i, 1893. 
ftU treated mainly from the poiot of view of the 
analytio ohemiit. The author appjkrs fairly well 
acquainted with what the German chemieta have 
' done in the matter of tea. 
We need not abstract much of his arcoant of the 
oonatitution and properties of tea. as it is largely 
taken from European sources. " The chief aotion of 
tea, after it has got into the blocd, is to excite the 
aervoui system, it thus harmonizes the mind, drives 
out drowRinesB, and awakens thought, etops hunger, 
and oures repletiou, refreshes the body, and prevents 
headache" — and (it might be added) if taken too 
■tronir keeps you awake balf_ the night. As to its con- 
Btitntlon, tea contains (betideti the common plant — 
oonstituents) theine, a volatile oil, and tannin. Th< ioe 
is a rank poieon, in toxic doses causing couvuliiions 
and paralysis, in lethal doses death, but in email 
quantities is (like strychnine) a delicate tonic. Of the 
volatile oil, Y. Kozai can ntlirm little beyond its well- 
known exciting aotion npou the or(;arB of taete and 
amell, nor is it easy to follow it enalytically through 
the processes of manufacture, the h<>t t'teamiug em- 
ployed (at near boiling temperature) in the green-tea 
mannfaoture does not appear to diminish the volatile 
oil sensibly, though Y. Kozai intimates that pre- 
paring green tea by boiling does dissipate ttie 
aroma. As to the properties of tannin, it is an as- 
tringent remarkable for its strong affinity for the 
albuminoid, benoe if taken in excean, it may, by pre- 
cipitating the ferments of the digestive fluids, cause 
indigestion. 
The aecoant of the chief Japanese methods of 
manufaoture is of more interest and instruction to 
the European planter. 
Wo may premise that there are two (main) kinds 
of tea, viz. black and green. In the manufacture of 
black tea there are four essential processes viz. d) 
withering, (2) rolling, (3) fermenting, (4) drying. In 
the manufacture of green tea, the fermenting is 
l^mitted, and in Japan (for some kinds of green) the 
oiling also. 
For the manufacture of black tea there is no real 
difference between the Japanese method and that 
practised by English planters in Bengal. The frcfth 
picked leaf (t. tips of the young ebooti) nmst be 
first withered, or the petioles and leaves break uuder 
the rolling, the exposure of an hour or two in strong 
■nn withers the leaf snfficiently, if there is no eun 
the leaf must be withered bv the aid of fire-heat. 
The rolling is done, even in Japan, by the aid usually 
of a box, and in Bengal often by a steam-power 
(and very roughly). The juioee are thus expressed, 
and the leaf given a "nice" twist, a twitt pleas- 
ing to the ftney of the tea-purchaser. What perhaps 
renders rolling so essential in the manufacture of 
black tea for it is not essential in the manutactare of 
grean), is that it masses the leaf in a state con- 
ducting tvithout delay to fermentation. Neither Y. 
Kozai nor the best Bengal authorities like to lose 
the juices more than oan be helped. He also hazards 
the view that, by rolling, the juice is expressed 
from the cellular tissues of the leaves and impreg- 
nated upon thsir surface thns is produced fine aroma, 
and the leaves are more easily infused. Fermenta- 
tion is the most important point in the mannfactare 
of black tea, and by it {Ade Y. Eozai) the leaves 
lose their raw smell, and the tea acquires its fine 
flavour. The fermentation is really only carried a very 
little way. Y. Kozai says it should be allowed, in a 
ttmperature of 104° F', to proceed only for about an 
hoar. He thinks the process it a trne fermentation, 
because il permitted to run too far the tea acquires 
an acid taste. He thinks it probable that the 
ferment is oauied by a living organism, but 
be adduces very slight ground for this opinion and 
it has, in fact, been questioned 'whether there it any 
true fermentation in the process at all. But the 
English tea-makers are agreed with the Japanese in 
the importance of stopping the fermentation exactly 
at the proper point by drying the tea which it usually 
done by placing it first in the aun and turning it over 
till it is fairly dry, and then thoroufihly drying it by 
The result of all the Bengal eiperi^nee Utbaltbe 
black tea js at least aa good when those four oro 
cesses are doce aimply and rapidly, m .hen uueb 
labour and time are expended in oomplieating them 
In the early daye of tta manufacture by Anglo-Indiana 
great pains were taken to imitate with tedious miunlt 
ness the careful hand-proce»». i, yand repetition* of por- 
tions of tie procewegjaapraftiaed in China but all plan- 
ters now follow rapid abort cuta to the finiahed tea 
The manufacture of green t*a ie nothing mor« than 
drying the leaf. It is so little practiaed in Britiah 
India as to be of no commercial intnrest there bat 
Y. Kozai deforibes in detail three kinds of green' tea 
maun^actured in Japan. 
1. Japanest (not China; ^r^en fro.— In tbi», the leaf 
is ateamed in order to remove the raw flavour II it 
then rolled and fire-dried, the two iaat processea beiuK 
ueually done together. 
2. CIn Mse 'jreen tta.—la this, the leaf it. roaate^l (whjie 
stirred with a atick) in an iron pan ov<-r a fire tb«o 
rolled a little, then roaHed again, the»« pr^aaa 
bemif repeated even eix or eight times, aud the tea is 
then finally dried off. 
3. Flat tfa, the highest olaHS tea of all For this 
tea, the shrubs are osuallv kept shaded for three weeka 
before pickiup bo that the leaf is partlv etiolated 
(bleached). The choiceat l.^ave» are aelect4-d before the 
manufacture is commenced. Thev are Rtearned Imt 
never rolled nor, indeed, touched by band at all but 
carefully turned by aid of a bamboo stick After 
sufficient steaming they are simply dritd. 
The author finds by analyaia that there is SO per cent 
naore theme in etiolated Uavea than in tbe leaves of 
the same plants grown in tbe light. He tried marv 
eiperimente to test the chemical effect of the manu 
factnriuB processes. Among other tibles given bv 
him IB tbe following :-A quantity of leaf was divided 
into three portions, whereof one portion i» another 
portion is manufactured into green lea B, the third 
portion is manufactured into black tea 0. Y Kozai 
analyses ABC and finds : — 
Crude protein 
Crude fibre 
Ktherisl extract 
Other nitrogen-free exti 
Ash 
Theine 
Tannin 
He remarks that the general result of the green 
tea manufacture is merely to dry the leaf the black 
tea manufaoture alters materially its chemical con 
Btitution. The principal change ia the remarkable 
diminution of the tannin. He does not explain how 
this IS brought about, nor it it easy to tee how tbe 
incipient fermentation should affect the tannin. 
The only teas exported to Europe from Japan are 
of low class, they are frequently «' faced," and some- 
times mixed with the leaves of various Japanese 
plants. Any plentiful leaf, not too unlike the leaf of 
tea will do for this adulteration, tbe leaves actually 
employed are (Y. Kozai atsnres ns) all harmless and 
several contain tannin, but none of them any theine As 
to the "facing," he savs it can hardly be called adulter- 
ation; the quantity of Prusiian blue employed to improve 
the appearance of green tea is (according to Y. Kozai) 
aboQt 0,001 per cent Ihe weight of the tea, perfectly 
innocent, and pleasing to the pnrohatar. 
The author concludes with an account "of tbo different 
ways of taking tea in Japan with some analvtei of 
tbe prepared liquor. 
1. In the case of flat tea, or of the very finest qoalltyof 
Japanese green tea, the tea is ground to fine powder, 
and the whole infusion drunk. 
(2) In the case of superior (».«., from the Japan 
point of view) tea, tbe leaves are infated for two 
minutes in water at 120° to 150° F. 
• i^^' J ■^P "^^^ °' * medium tea, the leaves are 
infused for one minute in boiling water. 
(4) In the case of inferior tw, the leaves are boUed 
m water. 
A 
B 
C 
87-38 
37-43 
38 90 
1044 
1006 
1007 
649 
652 
5-B2 
27 86 
31-43 
35 39 
4-97 
4-92 
4-93 
3.80 
3-30 
3-30 
1291 
10 64 
4-89 
