184 



ANNUAL OF SCIENTIFIC DI3COVI1KY. 



Each column represent* in cubic, centimetres the quantity to be added to 

 100 cubic centimetres of alcohol. 



Dingler's Polytech. Journal, clxxx. p. 407. 

 ABSORPTION OF GASES BY SOLIDS. 



Among the interesting observations of Mr. Graham, Master of 

 the British Mint, upon the passage of liquids and gases through 

 solids, is the fact that atmospheric air, by passing through India- 

 rubber, becomes super-oxygenated, and will rekindle smouldering 

 wood like pure oxygen. Any kind of light India-rubber receiver, 

 in which a vacuum may be'obtained, the size being sustained by 

 mechanical means, will collect super-oxygenated air; the better 

 if the India-rubber be thin and the temperature high. Mr. Gra- 

 ham makes the suggestion that the solid films pass gases through 

 them by first condensing them to a liquid form within the sub- 

 stance, and then passing them off on the other side by evapora- 

 tion. Hydrogen passes through red-hot platinum, while oxygen 

 and nitrogen do not, or not in appreciable quantities ; hence their 

 compounds with hydrogen are readily dialysed by this method. 

 The passage of carbonic acid, chlorine, hydrochloric acid, vapor 

 of water, ammonia, coal gas, and hydro-sulphuric acid, is also inap- 

 preciable, while the hydrogen, in compounds containing it, passes. 

 One volume of red-hot platinum absorbed 0.207 volume of hydro- 

 gen, retained it while cold, and gave it off on reheating. One 

 volume of palladium absorbed G43 volumes of hydrogen, sensibly 

 increasing its weight, and, when heated afterward, gave off the 

 most of it in a continuous stream. On the other hand, osmium- 

 iridium does not. absorb hydrogen, and copper absorbs it very 



