372 Apjjarat'un for Rapid Gas- Analysis. 



XXIV. — ApjKiratics for Rapid Gas- Analysis. 



BY ARTHUR H, ELLIOTT. 



Read March 5th, 1883. 



In many manufactories and metallnrgical Avorks, it is often 

 of great service to be able to make rapid analyses of tlie gases 

 resulting from various oi)erations, as these analyses serve to con- 

 trol the operations and indicate the progress of the ]irocesses. 

 This is especially true for iron and steel works, where a know- 

 ledge of the composition of the gases from a furnace is an index 

 of the character of tlie changes going on inside the furnace. 

 Such ]'a])id analyses ai'c also often needed in gas-works. 'J'o 

 meet this requirement of technical Avoiks, many methods have 

 been devised and various ingenions forms of apjiaratus have 

 been constructed. But all the appliances used for this purpose 

 have been based upon the princi})le of absorbing the various 

 gases in a mixture by liquid reagents. Of the many methods of 

 using liquid reagents, that of Orsat is probably the best known, 

 and the one that has been most used. In this apparatus the 

 gas, after being measured, is made to pass into vessels contain- 

 ing the liquid reagents, and so arranged as to expose a large 

 surface, wet with the reagent, to the mixture of gases. If time 

 is of little value, this apparatus works very well, but it is too 

 slow in its action to be desirable for use in technical works. 

 One great objection to the apparatus itself is the number of stop- 

 cocks attached to the various parts of it. These stop-cocks be- 

 come incrusted with the various reagents, and refuse to turn 

 without great trouble ; and any force applied to them is apt to 

 cause a fracture, which ruins the apparatus for further work 

 until the damage is repaired. 



Instead of passing the gas into a vessel containing the chemical 

 reagents, Kaoult* put the I'eagent into a tube containing the 



* F. M. Raoult, Cowpt. Rend , 1876, 844. 



