334 
Pernambuco Cotton. 
[Oct. 
the compound should give an abatement of full three per cent, in the price, setting 
aside all considerations of the utility of the tin being diminished by the adultera- 
tion. A small addition, however, of one or two per cent, of lead, would be hardly 
discoverable in practice. 
For the satisfaction of those who would repeat the analysis of any of the speci- 
mens, I beg to state briefly the process pursued. 
100 grs. were digested in boiling nitric acid until converted entirely into a 
white sub-nitrate. The solution was then evaporated to dryness, and the precipi- 
tate redigested in boiling distilled water, and filtered : the subnitrate convertc 
into a peroxide at a red heat furnished the proportion of tin, while the filtered 
liquor and washings concentrated and treated with sulphate of ammonia yielded the 
lead in the shape of sulphate : the remaining solution was tested with prussiate ot 
potash for iron and copper, and lastly with carbonate of potash for zmc. 
The peroxide of tin was separately examined for antimony, arsenic, tungsten, 'C. 
but without finding traces thereof, unless the yellow colour of the oxide might >c 
attributable to a slight contamination with antimony, a point requiring furt er 
experiment to determine satisfactorily, but from its minuteness, not of much con- 
sequence on the present occasion. I have since tried M. Gay Lussac’s met o o 
separating antimony from a nitromuriatic solution of tin by the immersion o a 
Mark on the 
Specific 
gravity. 
Malleability. 
Composition. 
Samples of 
Tin. 
Tin. 
Lead. 
A. 
7.33 
slightly rough on edges 
of laminated strap,. . 
99.8 
0 
B. 
7.31 
edges quite smooth, . . 
99.5 
0 
C. 
7.31 
ditto not quite so good, 
100. 
0 
D. 
7.32 
ditto, 
slightly rough, 
99.8 
0 
E. 
7.32 
98.8 
1.2 
F, 
7.33 
very smooth edge, .... 
ft 
97.0 
0.8 
G. 
7.34 
slightly rough, 
100.0 
0 
H. 
7.37 
smooth edge, 
98.6 
1.4 
fainter an w- 
trace of copper # 
iron. 
slight ditto. 
i i I rnh [I 
Calcutta Assay Office , 1 
25 th August , 1831. J 
XV . — Pernambuco Cotton in Ava. ^ 
[Extract from a letter from Major Burney, Resident, dated 10th October, 
* Since I sent you some of the Theenban-wa cotton, I have found two > o ^ ^ 
plants of the regular Pernambuco cotton. The Burmese call this also Tie ^ 
wa (ship or foreign) cotton, and describe it to be a perennial, growing 
tree in this country. Its leaves also are very large.’ e rn® cDt ’ 
A few pods of this were sent by Mr. Swinton, Chief Secretary to o' ^ 
to Fort Gloster, and were there immediately pronounced it to be Pernam » c0 ^ w 
of the seeds were presented to the Agricultural Society, and another porti 
the Botanical gardens. - n 
Previously to Major Burney’s discovery of the Pernambuco cotton ^ jjyck 
he had found another species, which is also a perennial ; the trunk bem 0 
as a man’s thigh, and admitting of a man climbing up it. 
