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NOTE ON FORMOSA CAMPHOR 
greatest readiness. Thallium possesses tlie property, in common with most soft metals, 
of welding by pressure in the cold. Rubbed on paper, it gives a dark streak, having a 
yellow reflection, which in a short time nearly fades out, but may be restored with an 
alkaline sulphide. Thallium is strongly diamagnetic, being in this respect nearly, if 
not quite equal to bismuth. It melts at 550° Fahrenheit, and distils at a red heat, evolving 
brown vapours into the air at a little above its melting-point. When a minute frag¬ 
ment of thallium, or of any of its salts, is introduced into the flame of a spirit-lamp, 
it colours it of a most intense green, which, when examined by means of a spectrum 
apparatus, appears to be absolutely monochromatic, communicating one single green 
line to the spectrum. This property of the metal is now too well known to require 
further remarks. From it the name thallium was chosen, from thallos , a green bud. A 
magnificent green fire for pyrotechnic purposes can be made with chlorate of thallium 
8 parts, calomel 2 parts, resin 1 part. The chlorate of thallium is a beautiful crystal¬ 
line, difficultly soluble salt, which may be prepared by dissolving the metal in chloric 
acid, or by mixing together saturated aqueous solutions of chlorate of potash and nitrate 
of thallium. It is anhydrous. At the present price of thallium its employment for 
pyrotechnic purposes would be out of the question; but a very little reduction in price 
would enable its magnificent green flame to be employed for ship-signals, for which 
purpose the extraordinary intensity and monochromatic character of the light would 
enable it to penetrate a hazy atmosphere without the change of colour suffered by the 
ordinary green lights in which baryta is used. The atomic weight of thallium is 203. 
This result, however, is not deduced from sufficiently accurate analysis to render it entirely 
trustworthy, and I am now engaged in determining the equivalent in a more accurate 
manner. The physiological action of thallium is a matter of some doubt. Some 
French chemists have said that it produces lowness of spirits, and causes loss of hair. 
I cannot say that it has produced either of these effects upon me, although I have 
been much exposed to the action of its fumes during the last few months, and have 
occasionally swallowed a few grains of its salts. The only effect which I have noticed, 
besides the staining of the hair and nails, is a corrosive action which the sulphate has 
on the skin, burning the hands, and rendering the epidermis yellow and horny. In this 
respect it acts like mercury salts. Several thallium salts are sensitive to light: the 
protochloride and double phosphate of thallium and ammonia are especially so.— (Read 
before the British Association.') 
“ NOTE ON FORMOSA CAMPHOR.” 
BY ROBERT SWINHOE, F.G.S., ETC., H.M. CONSUL AT TAIWAN. 
The manufacture of this article has for some years been monopolized by the Taotai 
(or head Mandarin) of the island, and its sale farmed out to wealthy natives. In former 
years, a good deal of the drug was clandestinely produced, and smuggled across to China, 
where it was largely bought up by foreign speculators, and carried to Hongkong for 
shipment to Calcutta, at which place it finds the readiest market, being used by the 
natives of Hindostan for lubricating the body and other domestic purposes. But now 
its monopoly is so closely watched that almost the entire trade in it falls to the lucky 
individual whose Chinese agents can secure the monopoly. This bad system has occa¬ 
sioned the price of the article in Hongkong to increase considerably in value, and to 
make the profits accruing to the fortunate monopolist almost fabulous. The cost of the 
drug, I learn, amounts to only G dollars at its place of manufacture. The monopolist 
buys it from the Mandarin at 16 dollars the pecul, and sells it in Hongkong at 28 dol¬ 
lars. The gigantic laurel (Laurus Camphora ) that yields the camphor, covers the whole 
line of high mountains extending north and south throughout Formosa. But as the 
greater part of this range is in the hands of the aborigines, the Chinese are able to gain 
access only to those parts of the mountains contiguous to their own territories that are 
possessed by the more docile tribes. The trees, as they are required, are selected for the 
abundance of their sap, as many are too dry to repay the labour and trouble of the un¬ 
dertaking. A present is then made to the chief of the tribe to gain permission to cut 
down the selected trees. The best part of the tree is secured for timber, and the refuse 
cut up into chips. The chips are boiled in iron pots, one inverted on another, and the 
sublimated vapour is the desired result. The camphor is then conveyed down in carts of 
