CAIN AND cleaves: CARBON IN STEEL 



395 



catalyzer was omitted, and its absence when the catalyzer was 

 used. The barium carbonate titration method, ^ recently de- 

 scribed by one of us, was used for the determination of the carbon 

 dioxide. 



The routine followed in making a determination consisted in 

 inserting into the combustion tube the boat containing the sample, 

 and connecting up the Meyer tube containing barium hydroxide 

 solution. While passing a slow current of oxygen the combustion 



fel 



c. 



•m>.;'^»m^^-^^m:,i^ 



Fig. 2. Cross-section of Furnace 



P, platinum tube; W , water cooled jacket ofi German silver; S, stopper, German 

 silver ; Ci, and C2, copper tubes soldered to the platinum tube. 



tube was brought to about 700° or 800° and kept at that tempera- 

 ture until the superficial oxidation of the particles was effected; 

 this required a minute or two; then the temperature was raised 

 to about 1000° and the combustion completed. As soon as 

 absorption of oxygen had ceased the blow-pipe flame was turned 

 on full, this stage of the combustion being continued twenty-five 

 to thirty minutes to insure that the oxides had been kept fused a 

 sufficiently long time. The Meyer tube was disconnected and 

 the determination finished by filtering off and washing the precipi- 



2 J. R. Cain. B. S. Tech. Paper No. 33; also J. Ind. and Eng. Chem. June, 

 1914. 



