May 2, t? 92 .] 
TME TROPICAL AQRIOULTURI8T. 
825 
merate a few of the best specimens derived chiefly 
from the materials known ns alumina and silica. Of 
these the turqnois is perhaps the most prominent, 
and certainly one of most popnlar. The tnrqnois 
consists of about two parts alumina, one ^art phos- 
phoric acid and one part water. The best color is 
a deep sky-blue, thouKli it is found in yarious shades 
of blue. It is one of the few precious stones which 
are not transparent. The finest mecimens come 
from Pei’sia, and inferior specimens fi-om many other 
places. 
The topaz, another favorite jewel of the second 
order, is found in two or throe different varieties. 
The original oriental topaz of the ancients, composed 
chiefly of alumina, was of a brilliant yellow color, 
and was very highly esteemed. In these later times 
it has become exceedingly rare, and more valuable 
even than the diamond. Its rarity is so groat, indeed, 
that it has practically gone out of the market, and 
the ordinan’ topaz of modern commerce is something 
entirely different, and much less valuable. It is one 
of the silicates, and is known as the Brazilian topaz, 
from the country of its origin. Its color is a lovely 
pink, and it is produced by firing. The metal is 
completely covered and encompassed with sand, which 
is then sabjectod to a very high degree of heat, and 
after the expiration of a certain time it is 
allowed to cool off gradually, and if the process is 
exactly successful the stone is found to have turned 
to a beautiful pink color. The operation, however, 
is a very delicate and difficult one, and many stones, 
in fact the great majority of them, are ruined. The 
heat may have been too n'eat, or not great enough ; 
it may have been applied too long, or not long 
enough ; the cooling process may have been too 
alow, or too quick. In either case the stone is ruined ; 
and probably not more thou one-tenth of the opera- 
tions aie entirely successful. This makes the Brazilian 
topaz not only beautiful but valuable. 
The zircon, hyacinth, jacinth, or jargoon, as it is 
variously called, is another beautiful member of the 
second class of gems, which is not as widely known 
as it ought to be. It is remarkable as being by far 
the heaviest of the precious stones. I'hose which 
are called zircons are brown, violet and green ; the 
hyacinths are red, the jacinths yellow, and the jar- 
goons greyish-white and pure white. They are found 
in Ceylon, Germany, France, tho United States, and 
many other places. 
The tourmaline is remarkable for its many and 
varied colors and groupings of shades and colors. It 
is composed chiefly of alumina and silica in about 
equal parts. It is found in Brazil, Ceylon, Siberia, 
Moravia, Elba, Sweden, Burmah, tho Tyrol, Canada 
and the United States. 
The opal consists of about nine parts silica and one 
art water. Its colors vary from chalky-white to 
luish-whito, from yellow to red, and kaleidosoopi- 
cally from one to almost any other color. In respect 
to this variability of color, and a sort of nn-sterious 
opacity, the opal is unique among jewels. For some 
absurd reason it acquired unpopularity long ago as 
being “ unlucky,’' but it is now becoming again a 
a favorite of fashion, as it well deserves to be. The 
best opals are found in Hungary and Honduras, but 
the common varieties are found more or less generally 
all over tho world. 
The chrysolite is a beautiful stone of a greenish 
yellow color, composed of silica, magnesia and oxide 
of iron. , , , , 
One of the best and most useful of the silicates 
is the garnet, composed of silica, alumina, and pro- 
toxide of iron. It isdistributed extensively all over the 
world in abundance, and is therefore not very 
costly ; but it is exceedingly beautiful, rivalling in 
appearance even the ruby. The predominant color 
is red, but it varies from a brown to almost a violet 
hue. Carbuncle is a name applied to all garnets 
that arc cat with a smooth rounding top. 
The moonstone is a species of feldspar. It is 
colorless, or only slighted tinted with blue, green, 
yellow and red, and is beautifully transparent or 
translucent. Tho lustre is vitreous, and a brilliant 
pearly streak of bright light plays in it from side 
to side. This stone baa latterly beooiue very popu- 
lar, and deservedly so. It is found chiefly in Ceylon 
and Switzerland, and occasionally in Bavaria, Green- 
land, Norway and the United States. 
Lapis lazuli, tho “sapphire" of the ancients, is an 
azure blue, and is used sometimes for purposes of 
ornamentation in tho jewelry line, though more gene- 
rally for works of larger dimensions. 
There remain to be considered hereafter a number 
of gems of the third rank, composed chiefly of quartz. 
SELECT EXTRA -TROPICAL PLANTS 
READILY ELIGIBLE FOR INDUSTR ALCUL- 
TURE OR naturalisation. 
By Baton Ferdinand von Mueller, k.c.m.q , &o. (Mel' 
bourne ; Printed for the Victorian Government by 0* 
(Troedel & Oo.) Price 6a. 
The eighth edition of a book, which has been trana- 
lated into German snd French, adapted for Indian 
climates, and modified for that of New South Wales, 
needs no recommendation. The mere mention of a 
re-i(Bue ii all sufficient. A bonk of this oharaoler, 
though to a large extent a compilation, is oao wbioh 
demands unusual knowledge end conaammstc judg- 
ment on the part of the compiler. Its great suooesa 
indiestes Ihst these requisitions have been met. 
Indeed, it is a book which should not only form part 
of the library of every cultivstor, but one which should 
be on the shelves of all those in any way interested in 
ecounmic botany. As a condensed enoyolopiejia of the 
Istter subject, the book, within its proscribed limits, 
has a value for a class of readers os uumerons, or more 
so, than (hose fur whom it was more immediately 
destined. Those plants which are of special interest 
or value are marked by an asterisk. In all, 2,485 
plants are mentioned, besides very many others, of 
which incidental mention only is made. In tho 
appendices, details are given as to the temperature 
and rainfall in various parts of tho oolcny of Viotoria. 
Lists are also supplied of the genera, arranged ac- 
cording to the purposes for which they are used, 
alimentary, textile, constructive, modioiiial, and so 
on. A systematic index is also provided, in which 
the genera are arranged under their respeotive 
natural orders. A list of synonyms and a geo- 
graphical index fallow, and tbeao are aaoceodod by 
detailed lists of plants which furnish a crop in one, 
two, throe, or more years, aa the case may be. 
Plant! adapted for very cold or very dry regions are 
separately enumerated, whilst the work ends with au 
iudex of vernacular names. The mere mention of 
some of the contents of this volumo ia suffioiont to 
justify onr remarks aa to its utility. But its author 
is not yet sati-fied, nor, indeed, would he or could he 
ever be. Accordingly, we find him, while approach- 
ing the eighth decade of bis life, hoping not, indeed, 
ttiat be may sea “many more editions of this work 
brought up to the newest standard,” but that he may 
“ perhaps still be able to publish one more edition 
before passing away." To thia end he aolioits that 
assistance which all who are able will obeerfully give 
to so valiant anil indefatigable a worker as Sir 
Ferdinand von Mueller. — Oardenen' C/ironiele. 
[We uan personally testify to the great value of 
this oompendiouB book 0 / teferenae.— Ed. T. A.] 
EGG-PLANTS. 
Rome time ago, in passing a frnit shop in Regent 
Street, I saw in the window some fruits of tho purple 
Egg-plant, Solanum Melongena. Of coarse, this is 
olusely allied to tho Tomato, but it dues not appear 
to have taken the fancy of horticulturists ; yet when 
cooxed, it is one of (he most delicious of vegetables 
imaginable, 
Aa there are Apples and Apples, so there are Egg- 
plants and Egg-plants, The white variety is some- 
times onltivaTil in India, hat it is the least valuable 
as it is rather bitter ; but the purple varieties are oulli- 
Tsted in fields everywhere, and much used by the natives 
and Earo{ eons. 
