Jan. 1, 1902.] 
THE TROPICAL AGRICULTURIST. 
499 
partly to the self-restraint of planters, who cur- 
tailed production by a finer system of plucking, 
and partly to the hand of Nature (which, after 
two successive years of abnormal fertility, stayed 
production in a great measure) —a complete change 
has supervened, ami supplies for the present 
season seem unlikely to do more than barely 
meet the consumption. So far only the prices 
of the lower j^rades of tea have responded ma- 
terially to the improved conditions, but now 
that the shortage of supply — especially from 
the Indian plantations— is becoming an accom- 
plished fact, it is fully expected that a higher 
range of prices will prevail. I do not wish to 
assert that we are yet altogether 'out of the 
wood ' ; indeed, I believe that planters may, for 
some time yet, have to strain every uer^e to re- 
duce cost of production, and utilise every device 
for attaining greater efficiency in the manage- 
ment of their plantations. But the outlook cannot 
exactly be said to be as gloomy, as it has been 
daring the last three years. On the contrary, I 
believe we are just beginning to see a little 
daylight ahead, and that your correspondent's 
article ought ratlier to have borne the 
device 'a gloomy past.' Considerable efforts are 
now being made to foster and extend new markets 
— as is, indeed, pointed out by your correspondent 
— and this with a fair measure of success ; but I 
admit still greater efforts are yet wanted in this 
direction. One point further only will I refer to, 
which is the allegation that planters in 1900 
* picke J the tea more closely, and so increased the 
output — thus intensifying the evil.' They were 
only prompted to do so (unwisely, I admit) owing 
to the extraordinary and unexpected rise which 
took place during 1899, when, owing to the peculiar 
position of the market, the veriest rubbish of tea 
f i e, the coarsest grades) commanded as good a 
price as those of a much higher standard, which 
sta e of affriirs continued up to well on in the 
Spring of 19Q0."—H dt C Mail, Dec. 13. 
MICA. 
A meeting of the Optical Sooietj" was held on Novem- 
ber 28th at the Technical Institute, Leonard Street 
E.G. The President (Mr Dixey) was in the chair, and 
after the routine business has been disposed of ha 
called on Professor Silvanua P Thompson to give a 
lecture on 
MICA. 
The resources of the Institute enabled the lectn''e t 
be experimentally illustrated, and it was farther mad^ 
attractive by a ooUection of the various kinds of mica' 
lent for the oooaEion by Messrs. Wiggins. Professor 
Thompson began by describing the uses of mica, it 
being used most extensively for lamp-chimneys and 
oven-windows, and for insulating-purposes. Mica ia 
often miscalled talc, which is a substance possessing 
very different properties. The following table showa 
the chief varieties of mica, and the differences in 
Optical properties ; — 
Index of 
— Sp. Gr. =— Angle Refiaction 
Muscovite 2*7-2-9 Biaxial 65°-750 1-561-67 
Phlogopite 2-72 Biaxial 7° 18© l'751-73 
Eiotite 2-7-3*l Uniaxial ^\ I 
(nearly) 
Lepidomelane 2.9..31 J Uniaxial ^} „ 
2innwaldite 29 Bia.xial 500-67° 
Jjepidolite 28 
M caisa complex silicate commonly oontainin<^ aln- 
minimu, sodium, potash, and magnesium LeDfdnli?! 
contains a good deal of J.thiam, fasily demon? ra id 
by holding a piece in the flame, whilst lepTdomeW 
a black mica, contains much iron. MnscovTe the 
commonest kmd known in tire middle as 
uscoyy glass," ^s found in Russia ; the othef kinds 
=1, u ■ "y inclusions some SDecimprxi 
shown being coloured by inclusions of thiu Dlites of 
garnet and tourmaline. Crystals of mica be]o£ to thi 
flexn io r '"'"u,°^""'*''i'« cleavage into 
MexiUe _ layers. Large blocks of mica are opsone 
but, curiously enough, are quite transparent Tn the 
Sed P™Pe^-ties of ^^fica are to be 
on ' ^tar-shaped figures which show 
on v'lewiijg some kmds ot mica by transmitted 
A phenomenon of star-shaped figures iJZaLn\ l: 
also produced on striking 'a plate of m'ica tfe-'fiJ„;e 
resulting varying with the kind of mica. On snlit't in^ 
and bending some kinds of mica flash/s of l lht 1"! 
seen, due to electrical disturbances. The optical nro 
and bv "LT%''"'' ''-"^ tourmlre fSc^LpJ, 
and by means of a polarising m.icroscope adantod to 
the optical lantern. The optic axes wei-rby tlfi'^con" 
tuvance shown to vary, those in which the an^?« 
between the axes is very small being canednniaxi! 
The axes, as seen in the polariser, Lxve the appear 
anceof an eye, and are called " houppes.'" Prof™ 
Thompson pointed out that even when plates of mLa 
tWs beTnZ'?f " strong light " houpp% a.^ een^ 
this being a phenomenon that has not been nrevionslv 
pointed out. An artificial mica much u ed fSu£ 
ting.purposes is made from waste pieces of mica bv 
piSe""' "^'^ ''^^ Platerundel 
Dec"^7!°°''''"'^"^ '''' meeting.-C^.«.-,« and 
( Biaxial & I 760-860 
I Uniaxial 
1 " 
OO 
PRODUCE AND PLANTING. 
THE DEUNQUENC1E3 OF THE TEA GROWER 
seem to supply inexhaustible material for criticisn, 
Between those good-natured friends who have theori^: 
upon the subject of tea planting, t^a raakeina th« 
labour question, and all kindred matters connected 
with tea garden life and wo,k, and others who are 
always ready .o come down heavily upon those who 
cannot command success all the year Lund, the tea 
industry in its adv rsity has suffered much of late 
We print in another column a communication ori 
the Indian tea trade which appeared i-i tho J 
I'^.e. on Fiiday la.t from ^raln^ta'^^ef r~f 
dent of that Journal It is not pleasant communi- 
cation, and the shareholders in tea companies 
whom we imagine it, was primarily intended, might 
reasonably think that not only had the Ind an ill 
industry gone, to use the language of Mr Mantalini 
to the "demniuon bow-vows." but tbafc the majoritv 
of tea growers, directors, and managing agents of 
tea property, together with the Tea Associations 
were grossly incapable people, deaf to the good sfl 
vice showered on them from all sides, and deserving 
of punishment which should include "something 
lingering, with boiling oil in it." Only two neocll 
come out of the business triumphant, and coiwcioua 
that they have done their duty."^ These arf he Z 
seeing wnter m the financial paper, to whom 
ference is made, and the correspondent himself 
One, or perhaps both of them, scenting destruc. 
tion coming full speed ahead upon the tet indnstrv 
five years ago, and divining that unless new markets. 
&o., were found at once, the position would ro 
from bad to worse are now in the Olympian 
position of being able to say, '• I to d yon so," 
■i 
