202 RESEAECHES UPON THE CHEMICAL TROrERTIES OF GASES. 



Ammoniacal silver nitrate Yellow precipitate, similar in appearance and properties 



to the preceding. 



Ammoniacal cadmium chloride White precipitate in flocculent masses, somewhat solu- 

 ble in the reagent and in water. Permanent, if 

 protected from the air. By oxidation is converted 

 readily, in the cold, into yellow cadmium sulphide. 



Arsenious chloride in dilute hydrochloric acid The fluid grows milky from floating oil drops, which 



gradually collect as a very heavy oil at bottom. 



Zinc sulphate in excess of caustic soda solution Unchanged. 



Potassium permanganate, 6 per cent, solution acidulated Rapidly bleached. Becomes heated from the intensity 

 by hydrochloric acid. of the reaction. ISTo sulphuric acid is produced. 



Lead acetate Straw-yellow precipitate, insoluble in acids and alkalies. 



Rapidly blackens. 



Potassium bichromate acidulated by hydrochloric acid. Promptly reduced to green chromic chloride. No sul- 

 phuric acid is produced. 



Bromine water Rapidly bleached. No sulphuric acid is produced. 



Mercurous nitrate Grayish-black precipitate. 



Bismuth nitrate Slowly forming black precipitate. 



Nickel hydroxide in water Slowly blackens. 



Ferric hydroxide in water Unchanged. 



Yellow oxide of mercury Turns slowly gray and finally black. 



Ferric chloride Rapidly reduced to ferrous chloride. No sulphuric acid 



is formed and no sulphur liberated. 



Potassium ferricyanide Reduced to ferrocyanide. 



Osmic acid Rapidly blackened. 



Potassium rutheniate Extremely slow and incomplete reduction. 



Hydrogen peroxide No oxidation to sulphuric acid occurs. 



Cerium dioxide in dilute sulphuric acid Quickly bleached. 



Litharge and white lead Quickly changed, yielding a voluminous yellow powder. 



Copper carbonate The resulting mercaptide is similar in appearance to 



that obtained in the preceding reaction. The mer- 

 caplides of lead and copper are very stable. 



Silver foil Is not changed, dry or in water. After three months 



the silver appeared slightly darkened in color. 



Comments. — In the remarkable diversity of its reactions, methyl hydrosulphide 

 probably excels every other known gas. The stability of many of its metallic com- 

 pounds is often nearly as great as that of the con-esponding sulphides. The reagents 

 emploj^cd include many substances of high oxidizing power. It was not possible, 

 however, to detect in any case a trace of sulphuric acid. Under the influence of 

 oxidizing agents, the tendency of the mercaptans is to produce oxygen compounds, 

 such as the sulphonic acids. 



CH3SH -f O3 = CH3SO3H. 



Hence the failure to form sulphuric acid. The following experiment illustrates 

 the remarkable stability of methyl hydrosulphide : 



The gas was passed in slow stream through a glass combustion tube containing 



