736 
THE TROPICAL AGRICULTURIST. 
[May I, 1894. 
per cent of the total alkaloid present in the leaf is 
extracted, the other half remaining in the leaf 
together with the greater part of the tannin." Re- 
garding tannin itsolt we learn that "a solution of 
tea when allowed to stand tor some days, gradually 
loeea its astringenoy owing to a portion of the 
tannio aoid undergoing a ohemioal change from the 
absorption of oxygnn. This change wouU go on 
in imperffotly dried leaf, and the mellowing 
of tea when kept for a long period is 
probably due to this, especially as is seen from 
analyses of Indian teas made in England, that 
the average pGrcentage of tannic aoid present ie 
less than that found in freshly-made tea in this 
country," We, therefore, see that whereas the 
flavour and aroma due to the " essential oil 
suffer by exposure, tea is in other respeols im- 
proved by the hygroscopic moisture it absorbs." 
Farther on Mr. Baraber remarks :—" The tannin in 
tea is the chief oanse of strength and pungency, *" 
but it is probable that the fulnese of the tea apart 
from pungency is due to the mucilaginous consti- 
tuents dissolved by the boiling water as well aa 
to the tannin and other soluble matter." We 
potice here, as in many other places, that often 
where we long for more definite information, the 
aoientist speaks in terms of doubt and uncertainly 
showing that much has yet to be learned by our 
teachers. This " other soluble matter " is chiefly 
" mucilage," to the presence of which we are 
told " the creaming of tea is apparently partly due." 
I^inally, as regards the " theine," Mr. Bamber 
repeats in summing up the results of his analyses 
that " the total quantity present in the leaf and tea 
was 4'25 per cent showing that no loss of this 
oonatituent takes place during the various processes 
of manufacture" ; but as regards " tannin," he says, 
on the contrary, " a large proportion is altered 
and its astringenoy destroyed during the oxidation 
and firing proceBsea, without, however, reduciag the 
total amount of soluble matter ia the leaf. The 
quantity of soluble matter varies considerably 
throughout the season, depending largely on the 
kind of weather previous to, and at the time of, 
plucking." 
We now come to the more practical part of 
the BUbjeot in the Seventh Chapter in which Mr. 
Bamber very Wisely sums up the lessons suggested 
by bis researohea without re-intruding those 
Boientifio details to be found in the earlier 
OhaptetB. 
The avesage planter recoils from the mere 
teohuioalities and tables of a dry, unfamiliar science, 
^ith whose symbols and terminology he ia un- 
acquainted. The scientific expert sbouii endeavour 
to keep these for his own convenieooe, and to 
oommuatoste the results he arrives at in the 
simplest laBguage at his oommand. This, we 
apprehend, is -what a community of practical men 
want, and must have, in order to arrest their 
attention; and this, it seems to us, Mr. Bamber 
has well kept in view in the chapter on " manu- 
facture." In our notice of this part of Mr. 
Bamber's work we shall pass over the historical 
reterenoea and refer only to the useful hints and 
BUggestioQB that may seem to be novel and of 
value to our planters, reminding our readers, a*; 
tha same titos, that there is scarcely a lihe without 
tta intetest and importance. Of course, "witheriag" 
^eooapiett >tbe fivss place, and we are not surprised 
'to 'learn ' intamaah aa the chief object of 
1vUheiring-:4B to obtain the leaf in a suitable 
'^cy^itian ' for volling— thia ooaditioa being attained 
iWlHiu ^be ' 4eaf will take a f^d "-twist without 
'"fietng ' tlttaiotebdi — good ^tea coan uiba made litom 
'tkb&oti t^TOJ «y8temt 'artificial (or jothezwise.o pro- 
">vided the tempstAture employed is not ^00 high. 
or the prooeea not too nuieh prolon^^ " 
there '' i« little cbemisal change in the leaf duriua; 
the process of withering," it becomes more cr 
less a mechanical prooese, already well anderetooi 
and practised in our CuyloQ factories. " The 
amount of moisture which should be aHpwed to 
evaporate varies eoneiderably ccoording to the j^t 
of leaf, the time of year, sod the weather, but 
about 33 per cect apparently yields the bast 
results." " Rolling " comes ne$t, and we are told 
that *' certain chemical changes take place duiiag 
this process being more ^ron uncel when the 
tempera' ure of the leaves is allowed to rise and 
the rolling long maintained." 
Mechaoioally what takes pltee is "the breaking 
up of the cellular matter of the leaf in order to 
liberate the juicee, and to give a twiet or roll to the 
leaf, the tougher epidermis beiog merely bruised 
and twisted." The obanges that take place during 
rolliqg, Mr. Bamber insists. " should bo minimized 
as much as possible by keeping the leaf cool." 
These changes should take place during the 
" oxidation prooeEH" or, as commonly called, 
"Fermenting." This process, Mr, Bamber sayci, 
" is perhaps the moat important in the whole 
manufacture, as bulb the good quality and appear- 
ance of tea depend largely on the process being 
properly carried out." He advocates a special room 
for this process, kept damp by spriokliog cold water 
over the floor, and the leaf itself, when too dry, 
should aho be damped with clean cold water, 
and be protected from draughts by means of wet 
cloths placed over the heaps. Firing or drying, 
we are told, " should not be delayed for even a few 
mioutes after the leaf has attained ita proper 
colour, as it rapidly becomes darkened and the 
liquor and infused leaf will not be so 
satisfaotory. The temperature of the drying 
machine should be about 280°, and in that it should 
remain only until it ie half dry, when it can be 
allowed to cool and remain untouched for some 
time without harm The air of the drier should 
itself be as dry as possible. For the second firing 
the temperature should not be quite so high as that 
of boiling water, or from 180° to 200°, so as not to 
drive oti the essential oil usually lost at this time. 
But finally, in order to drive ofi all the moisture, 
the tea should be subjected to a temperature 
of about 212°, and the whole process of second 
firing should be slow, often ccoupying two hours to 
accumplish, in order to retain all the essential oil, 
and it is genera'ly believed that exposing the !eat 
to a prolonged gentle heat developes more fu ly 
the peculiar aroma of good tea," The " fi ial" 
firing takes place after sorting, during wijich process 
it has absorbed a oouEiderable amount of moisture 
from the atmosphere. This, in the final firing at 
about 212°, is driven oS, and the tea is then- 
after being allowed to cool down to a temperature 
a little above that of the surrounding atmosphere 
under dry clothes, and in the driest portion of the 
factory — packed in the usual air-tight, lead-lined 
boxes." 
Thus far we have followed Mr, Bamber in the 
various prooecses involved in the manufacture of 
tea ; and (although soma interestiog facts have 
been disclosed) we cannot oonscientioosly aay that 
anything very sirikiogly new has been evolved in 
the proceeding. Nor has much been explained 
that was no^wsH understood before. Still it :s 
something gained to be assured on scientific auth. r- 
it.y that the various processes followed in our 
factories are right. Keeping the leaf cool duriog 
rolling has long been practised by our planters, 
,and patentesB of rollers h^ve always made 4hia. a 
dOhief reoommeaiation of their mai9hi.ies. To get 
an even " withar" vast stuns Ijave been sjpgat oa 
