92 W. G. Miater—Estimation of Sulphur in Coal. 
of the apparatus are sufficiently tight when water will stand in 
one limb of the safety tube. : 
The bottle a is filled over water with oxygen, and, if necessary, 
rinsed with distilled water; a few drops of bromine are poure 
in, the tubes adjusted and aslow stream of water made to flow 
through the water-jacket. The assay, if not volatile, is intro- 
duced into the tube din a platinum tray*, which should not fill 
more than half the bore of d, leaving space enough for the free 
circulation of the oxygen. The partc is gradually heated and 
kept hot during the combustion. This hot inclined tube acts 
imney; the heated gases rise in it, pass into the cold 
tube 4 and fall, thus causing a constant stream of gas to pass 
over the assay. It is important to ignite the assay without 
phuric acid are formed in much quantity, the volume is dimin- 
ished and air enters through the safety tube. 
mixed with sand in suitable proportion they burn slowly and 
completely. Liquids shonle i 
sealed at one end and drawn out at the other to a capillary bore 
for two or three inches of length. Upon the point of the tube a 
bit of platinum sponge is fixed to assist the oxidation. The 
liquid should not fill more than two-thirds of the wider part 
of the tub 
Before introducing very volatile substances, the 10 cm. of 
the combustion tube 7d should be heated to dull redness. 
* A platinum tray which answers well may be made 10 to 20 em. long, 10 mm. 
wide, and 7 to 10 mm. deep by bending thin foil over a glass tube. The ends may — 
be roughly bent together or left open. 
