1831.] Examination of a Metallic Button, eSpc. 39 
not find it advantageous. His overseer gave me a piece of it crystallized, which dif- 
fers, in some respect, from any calcareous spar that I have seen. I myself found no 
crystallized matter in any of the asnrhar. This substance is also found close ad- 
joining to the hot sources of the Angjana river, and by the natives has been wrought 
to a trifling extent. It is in a stratum about a foot thick, lying on loose siliceous 
stones, to which it adheres, and is covered by about a foot of soil, mixed with stones. 
So far as I saw, it contains no animal exuvia. 
On the stones, through which the hot water issues, both at the sources of the 
Angjana and at Bhimbandh, there adheres a tuaceous matter, so like this as-urhar , 
that I, at first sight, concluded it to be the same ; but on trial, I found that it does 
not effervesce with the nitric or muriatic acids, and is probably of a siliceous 
nature. 
I have already mentioned the pyrites found in the slate, and they seem to be 
ferruginous, but the quantity is very small. Among this class of minerals, the only 
iron mines of which I heard, are in the ridge which extends east to Jathaurnath ; and 
as they are on the borders of the 3d division, which abounds in similar mines, I sus- 
pect that they, in fact, belong to this division, and one description may serve for 
both. 
II . — Examination of a Metallic Button, supposed to be Platina, from 
Ava. By J. Prinsep, Esq. F. R. S., Sec. Ph. Cl. As. Soc. 
[Read before the Physical Class of the Asiatic Society, 15th Jan. 1831.] 
The specimen was transmitted from Ava, by Mr. Charles Lane, through Major 
Burney, the British Resident at the Burmese Court, along with a variety of the 
mineral products of the Burmese empire. It was accompanied by the following 
notice from Mr. Lane, on the subject of its locality and extraction. 
Mixed with the gold dust, found to the northward of Ava, are a quantity of 
grains of metal, having every appearance of iron ; they are easily corroded, and are 
also affected by the magnet : by melting these grains, and keeping them in fusion, 
until the metal is no longer observed to scorify, the enclosed button of metal is left 
at the bottom of the crucible. 
This metal, when mixed with gold, is found to increase its brilliancy. The King’s 
earrings are made of a small quantity of it, mixed with pure gold ; it is very brittle, 
and all our attempts have hitherto failed in making it malleable.” 
Chemical Examination. 
1. Ihe specimen was in the shape of a bright metallic button, weighing 45 grains, 
of a colour similar to platina. 
2. The specific gravity was found, on three trials, to be 17,2 : it did not visibly 
affect the magnetic needle. 
3. When struck lightly with a hammer, the bead broke into several pieces, the 
largest of which was preserved, as a specimen, for the cabinet. 
4. Another piece, weighing about 13 grains, was heated under a muffle, at a tem- 
perature of 1900°. It lost all brilliancy, and assumed a dull granular spongy tex- 
ture, and a dark black colour j without loss of weight. 
Heated strongly in a forge, it fused into a hard brittle button, with tarnished sur- 
face, and bubbles of air within : the loss amounting only to one 500dth. The 
same bead, again heated red with borax, held by a platina spring forceps in the 
blowpipe flame, was compressed and soldered to the forceps. The exterior coat 
imparted a dull green colour to the borax, and the bead retained all its brittleness. 
