490 Dr. C. R. A. Wright and Mr. C. Thompson. 



of current had passed to about saturate with oxygen or hydrogen 

 respectively the fluid in the collecting tube, and so avoid loss by 

 solution ; in the first set the alkaline fluid was strong caustic soda solu- 

 tion ; in the second somewhat diluted sulphuric acid (1 to 4 or 5 

 water) was the acid liquid. Carbon plates were used in experiments 

 G and H ; platinum ones in all the others. 



I. Cells in which Oxygen was evolved. 



A. Becquerel's "pile a oxygene." Concentrated nitric acid used. 



B. Diluted sulphuric acid in which potassium permanganate had 



been dissolved. 



C. Diluted sulphuric acid in which potassium dichromate had been 



dissolved. 



D. Diluted sulphuric acid in which potassium f erricyanide had been 



dissolved. 



E. Acid solution of ferric chloride. 



F. A stronger acid solution of ferric chloride. 



G. Hydrochloric acid saturated with chlorine. 



H. Diluted sulphuric acid containing dissolved bromine. 



Time in hours. 



Milligrams of 

 silver deposited. 



Cubic centimetres of oxygen at 0° and 

 760 mm. 



Equivalent to silver. 



Actually collected. 



A. 18 



102 



5 '3 



5-1 



B. 10 



85 



4-41 



4 '30 



C. 18 



16 



0-83 



0-80 



D. 42 



12 



0-62 



45 



E. 48 



5 



0-26 



0-25 



F. 48 



18 



0-93 



0-85 



Gr. 18 



25 



1-30 



1-4 



H. 18 



46 



2'38 



2*3 



II. Cells in which Hydrogen was evolved. 



I. Concentrated solution of sodium hyposulphite (hydrosulphite 

 Schiitzenberger) made strongly alkaline with caustic soda. 



J. Strong caustic soda containing pyrogallol dissolved therein. 

 K. Alkaline fluid obtained by dissolving cuprous chloride in 

 ammonia. 



L. Similar fluid obtained from ferrous sulphate, ammonium 

 chloride, and ammonia. 



