METHODS OF ANALYSIS 19 



5 cc. of HC1. Evaporate to dryness and dissolve the residue with 

 10 cc. HC1, boil, add 15 cc. water, boil, allow to settle, filter through 

 9 cm. filter, treat the residue with 1 cc. HC1, boil, dilute with water 

 and wash into the filter, cleaning out the casserole with a finger 

 cot. The filtrate will contain, generally, Ag, Cu, Pb, Fe, Al, Mn, 

 Zn, Ca, and Mg. Add ammonia until slightly alkaline, then about 

 8 cc. sulphide of ammonium and 10 cc. carbonate of ammonium, 

 and boil for three minutes. Remove from the heat, allow to settle, 

 filter rapidly into a No. 3 beaker, washing the ppt. three 

 times with boiling water containing a little sulphide of ammonium. 

 To the filtrate add HC1 until slightly acid and boil down rapidly 

 to about 50 cc. Filter out the sulphur and add bromine water to 

 the filtrate until it clears, boil out the bromine, then make alkaline 

 with ammonia and add 5 cc. ammonium oxalate to remove the small 

 amount of lime still remaining. Boil, let settle, filter and wash, 

 evaporate the filtrate to 50 cc. and cool by dipping the beaker into 

 cold water. Add Na 2 HP0 4 and NH 4 OH, and proceed as in magne- 

 sium in slag. 



Alumina, Etc. — A hydrochloric acid solution of the soluble 

 portion of the ore is obtained, the insoluble residue ignited and 

 weighed in a platinum crucible, fused with alkaline carbonates, ex- 

 tracted with water and HC1, evaporated to dryness to separate 

 silica. Then proceed as in slags, after adding the portion solu- 

 ble in acid above. 



COAL AND COKE. 



Proximate Analysis (Heinrichs). — Weigh out in duplicate 1 

 gram of powdered coal; place in a small beaker, covering with a 

 watch glass, and place on the steam dryer for 24 hours. Take off 

 and weigh; the loss found x 100 = $ of moisture in the coal. 



Weigh 1 gram of the powdered coal into a medium-sized por- 

 celain crucible, put the cover on and place the crucible in a medium 

 hot muffle and allow it to remain until fumes cease to come out 

 around the edge of the cover. Remove, cool, and weigh; the loss, 

 less the moisture previously found, x 100 = $ volatile combustible 

 matter. This should also be done in duplicate, and results should 

 check. 



After weighing the volatile matter, put material back in the 



