45 S 
THF TROPICAL A0RI0ULTURI8T. [December i, 1890. 
obtained the alumina in a crystallised form, and if 
chromate of ammonium was present the crystals 
were to all intents and purposes rubies. Again, 
Sainte-Claire, Deville, and Caron heated fluoride 
of aluminium, fluoride of chromium, and boric acid, 
and in this way obtained fluorids of boron, which 
escaping in a volatile condition left a residue of 
solid alumina coloured by the chrome. 
These results, it may rightly enough be urged, 
were mere laboratory experiments. But the manu- 
facturer of precious stones has gone a great deal 
further than this s'age, and it is certain will 
proceed far beyond the milestone at which it is 
at present resting. For in 1878 Fremy and Feil 
reproduced the ruby and sapphire on a large scale, 
by heating in a fire clay crucible a mixture of 
alumina and red lead. The result of this fusion 
was a vitreous silicate of lead (the silica being 
derived from the crucible) and crystallised alumina. 
When to this bichromate of potassium was added, 
the aluminia assumed the desired tint of the ruby. 
By this process spinels have been produced quite 
undistinguishable from the natural gems, even 
when the most minute tests were applied to them. 
It cannot, perhaps, be claimed as yet that such 
laboratory jewels will satisfy all the requirements 
of the cutter and polisher, but when this point 
his been once attained, it is certain that they 
will soon run the real, or rather the old fashioned, 
article very closely. The most pessimist of sceptics 
cannot carry his prying so far as to apply the 
test of the knife-point for hardness of the acid 
for composition of the dichroiscope for “pleio- 
ohroism,” or ask the wearers to allow their jewels 
to be weighed for specific gravity in Sonstadt’s 
solution. And if not, who need trouble themselves 
further? Family diamonds are costly articles to 
keep simply for the gratification of the owner’s 
knowledge that they were dug out of the mines 
of Golconda or of Minas Geraes, and they would 
soon be locked up in safety if a set externally 
identical could be bought at a twentieth of the 
price. Already, in fact if only a portion of the 
tales told are true, prudent people are growing loth 
to keep in their jewels oases exposed to the risk 
of robbers, convertible securities representing an 
income of four or five hundred a year, when the 
ingenious artists of the Palais Eoyal can supply 
something undistinguishable from them for a 
very moderate number of francs. These jewels, 
which are mere imitations, not chemical reproduc- 
tions like the gems mentioned, far surpass the old 
paste mimicries, their only fault being that if 
anything they sparkle rather too brilliantly. Some 
of them of which the basis is glass, are rather 
coarse. But there are others of such amazing 
perfection that an amateur runs serious risk in 
buying from unknown dealers on his own un- 
assisted judgment. Amethysts in an especial degree 
have been made so fine that they have deceived 
connoisseurs, and numbers of them are regularly ex- 
ported to Ceylon, where they are duly disposed of to 
the unsuspecting passengers of steamers hailing at 
Colombo. Since the decrease in price of the real 
stones the danger of imposition is less, yet a 
case occurred not long ago in which a jeweller 
declined to pronounce on the value of a “ stone,” 
until he had submitted it to an expert, when it 
was pronounced one of the Parisian sort . — Indian 
Ai/riculturist. 
^ 
Tin; Achtiialian “Suk-oak” (Caspahina) 
is prospering in Aberdeenshire. “ Old Colonist ” 
who considers it the very best firewood the world 
produces, reports that from seed gathered by him 
in Tasmania, trees are now flourishing on Daesido 
and their growth is equal to 18 inches in the twelve 
months. 
PADDY (RICE) CULTIVATION IN CEYLON. 
We call attention to the able letter on page 462, in 
which Mr. Elliott — in his own name — justifies his 
position in reference to the recent experiments and 
discussion connected with Paddy Cultivation. There 
can be little doubt that Mr. Elliott has a more 
intimate and practical acquaintance with his 
subject than any of his critics— whether offi- 
cial or unofficial — and we may say than any 
other public servant in Ceylon. Hs has 
been consistent too in, for many years, uphold- 
ing the view he has adopted and while our 
own inclination has been to limit the profitable 
cultivation of paddy to select divisions of the 
country — a limitation in which to a great extent 
no doubt, Mr. Elliott agrees — yet, we are bound 
to confess that he has given us reason to believe 
that rice cultivation is far more widely profitable 
in Ceylon than wo had at all believed before 
Mr. Elliott engaged in experiments or wrote ex- 
pcessly on tke subject. 
Western AusTBALiAis certainly the coming 
Colony if, as a telegraphic report has.it, an expert 
values its forests alone at a hundred millions ster- 
ling, as their present marketable value. We in 
Ceylon should be greatly interested ia our nearest 
neighbour ; for as its population leaps up by thou- 
sands and perhaps hundreds of thousands, we 
ought to do a good trade in supplying them with 
all the tea, cocoa &c., they require. 
Boecteic Lighi Effects on Cane Gbowth. — A. s 
it is a well known fact that the growth d cane or any 
other vegetation depends perhaps as much upon light 
as on heat, and that a large amouut of sunshine 
is very desirable to secure the rapid growth of cane, 
the thought has been suggested that electric lights 
may yet be used to advantage to pr 'mote the growth 
of sugar in this latitude, where forcing is desirable 
if not absolutely necessary. At first thought, almost 
any one would be incuned to ridicule the idea. 
Still, we notice that our tropical exchanges consider 
that when they have slor.ns that electricity plays 
an important part in llio growth of cane. Is 
it not possible that where many electric lights ate 
used, that the air to a certan extent becomes charged 
with that powerful el.ment? If not, certainly light 
has great influence on vegetation, as science lias 
proven ; and this brings the thought that the “moon 
philospliers” may be partly right in their planting 
theories — or, that the light of the moon may produce 
that effect ou vegetable growth that they attribute to 
something else. — Our attentio i was recently called 
to this subject by a friend, who said he thought 
he saw a greater leaf development on trees and 
shrubs on the side adj icent to electric lights. 
Later, he made the following clipping from a 
technical journal, which shows that it is a fact — and 
possibly a most important one for cane growers — that 
electric light has great intluence on vegetable growth : 
— “ A beautiful illustration of electric light on plants 
was recently given by Dr. Si* mens before the Royal 
Society of England. He placed a pot of budding 
tuhp.s ill the full glare of the electric light in the 
meeting room, and in about 40 minutes the buds 
bad expanded into full bloorri. In giving a statement 
of some of bis experiments, Dr. Siemens said that he 
had p'anted a number of qu'ek growing seeds in 
pots, and divided the pots into four groups ; one 
group he had kept entirely in the dark, another he 
had exposed to the influence of the electric light 
only, ar, other to llie influence of daylight only, and 
luiotlier to electric light and daylight in succession. 
Death eooii resulted to those plants which were kept 
entirely iu tlie dark; those exposed to the electric 
light ouly, and those exposed to the daylight only, 
throve about tqually; and those exposed to both day 
and electric light throve much better than cither.” 
— iiuyar Bowl and Barm Journal. 
