114 ANNUAL REPORT 
ceed with the determination of the lime. Should a trace of manganese 
dioxide separate on adding the ammonium hydroxide, continue the heat- 
ing till it dissolves and the solution is nearly colorless before precipitating 
the lime. 
Determination of Sulphur in Slag. —The sulphur in slag is usually 
present as calcium sulphide. For the purpose of determination the sul- 
phur may be brought to the condition of the sulphate in two ways, the dry 
or the wet method. The former is acomplished by careful fusion with 
alkaline carbonate, the latter by treatment with acid and oxidizing agents 
like bromine or chlorine. 
Fusion Method.—Mix 1 gram of the finely pulverized slag with 6 
grams of sodium carbonate and 0.5 to I gram of sodium nitrate, according 
to the amount of sulphur expected. Put the mixture in a platinum 
crucible. Put a heavy layer of sodium carbonate on top of the mixture 
and fuse carefully. As soon as it is well melted, chill the crucible by 
dipping the bottom into water. ‘This will loosen the cake so that it can be 
removed. 
The fusion must be made over an alcohol or gasoline lamp. Boil 
out the fusion in the water till all the material is soft and no hard lumps 
remain. If the solution is colored by Na,Mn,O, add a few drops of 
alcohol. Filter and wash well with hot water. Add HCl to the filtrate 
till just acid, evaporate it to dryness carefully and dry at 100° C. Now 
add 5 cc. of hydrochloric acid first diluted with its own volume of water. 
Warm and add 50 cc. of water, heating till everything is dissolved but a 
little SiO,. Filter and wash. The filtrate should not exceed 100 cc. If 
it does, concentrate it. Now heat nearly to boiling and add 5 to Io cc. 
of a 10 per cent. solution of barium chloride, previously diluted with 
10 to 20 cc. of water and heated. Stir and let the precipitate of barium 
sulphate settle; when clear, filter, wash with hot water, ignite over 
Bunsen burner, cool, add one or two drops of sulphuric acid, ignite 
again and weigh the BaSO,. Calculate the sulphur. 
Wet Oxidation.—Place sample of I gram into a hard glass bulb 
provided with a three-hole rubber stopper. In one hole there is inserted 
a separatory funnel, through the second a tube connected to a Winkler 
absorption coil containing bromine, while through the third connection 
is made with an air supply tank, containing air under low pressure. 
Bromine water is poured over the sample in bulb and hydrochloric 
acid is added slowly at intervals through the separatory funnel. The 
hydrogen sulphide evolved is oxidized largely by the bromine in the 
bulb, and any gas escaping is taken care of by the bromine water in the 
coil. During the reaction the bulb is shaken occasionally. When the 
decomposition is finished, heat to boiling and allow to cool slowly. The 
contents of the bulb and coil are now united, the excess of bromine is 
