1874.] Technology. 139 
the papers as communicated by the authors to the “Chemical News,” and 
which must be regarded as a valuable contribution to chemical and physical 
science. 
TECHNOLOGY. 
An instructive paper by Capt. G. A. Strover, of Mandalay, on the Metals 
and Minerals of Upper Burmah, appeared in the ‘‘ Chemical News ” of O@ober 
to. Gold, silver, copper, iron, lead, tin, platinum, graphite, coal, jade and 
amber, sulphur, saltpetre, rubies, sapphires, garnets, salt, petroleum, india- 
rubber—all seem to abound. The sulphur is found in efflorescent salts, and is 
manufactured from metallic sulphurets. The mode of extraction is illustrated 
below in Fig. 15. Common chatty-shaped vessels are made on the spot from 
Fic. 15. 
Sar y i, & Ve ze— wie 4 = os 
Sa WAZ. A= NE a tea a 
the soft blue clay in which the ore is found. The larger vessel is filled with 
broken ore, and placed on a fire, a clay retort being fitted to the top, and com- 
municating with the smaller vessel. The sulphur is thus sublimed and 
condensed as shown, after which the retort is broken, and a hollow tube of 
flowers of sulphur extracted therefrom which is superior to that condensed in 
the vessel. 
The following improved forms of gas generator were described at the 
Bradford Meeting of the British Association by Mr. C. J. Woodward, 
B.Sc. :—Two forms of apparatus had been made. The first, shown in section 
in Fig. 15, and intended for large supplies of gas, consists of a circular stone- 
ware vessel, A A, holding 3 or 4 gallons, and surmounted by a large cylindrical 
pipe, B. In the top of the vessel is a tubulure, c, to which is fitted a glass 
cylinder containing the granulated zinc or other gas-generating material. To 
the opening of the upper end of the glass cylinder is attached a cork and the 
delivery tube,p. A plug, E, can be raised or lowered by means of a cord, 
which, passing over pulleys, terminates in a ring, F. It will readily be seen in 
what way the apparatus is used. As seen in the figure, the plug, &, is 
immersed in the acid with which the stoneware jar is filled, and the liquid has 
risen by displacement into the glass cylindrical vessel, coming in conta& with 
the gas-generating material, where of course the evolution of gas goes on. 
When it is desired to stop the flow of gas, the plug, £, is raised, the ring, F, 
being slipped over the stud,G. The acid now retreats from the glass cylinder, 
and the gas-generating material is left dry. At any time, then, when gas 
is wanted, it is only necessary to release the ring, F, the plug, £, falls into 
the acid, the zinc, marble, &c., becomes covered, and the flow of gas begins 
and can easily be arrested in the manner first described. The second form of 
apparatus, used when only a small supply of gas is wanted, consists of a 
Wolft’s bottle, a, Fig. 16, to one tubulure of which is fitted a cork carrying a 
glass tube and piece of caoutchouc piping, B. This pipe, B, can be closed by 
a pinch-tap, c. To the other tubulure of the Wolff’s bottle is fitted the 
adapter, D, in which is placed the zinc, marble, or other gas-generating 
material. To the upper end of the adapter is fitted a cork and tube, E, serving 
for the escape of gas, which is washed at F, and then passes on foruse. To 
use the apparatus, the Wolff's bottle is charged with acid up to the level indi- 
cated in the figure. Then, on blowing air by the mouth by means of the tube, 
B, the pinch-tap, c, being open, acid is forced into the adapter, D, and gas at 
