192 Mr GRAHAM'S Account of the Formation of Alcoates. 



length, filled with small fragments of chloride of calcium. Thus 

 dried, the deutoxide of azote was passed slowly over carefully 

 prepared protochloride of iron in the state of poAvder, and con- 

 tained in a glass-tube of small diameter. The protochloride im- 

 mediately became darker in colour ; and upon being withdrawn, 

 after exposure to the current of gas for some time, was found to 

 retain the smell of nitrous gas, and to have increased in weight. 

 In one case, 30 grains chloride had increased to 31.1 grains ; 

 and in another case, 25 grains chloride to 25.5 grains. On be- 

 ing gently heated, the deutoxide of azote was evolved, and the 

 chloride restored to its former colour. 



The solution of protochloride of iron in absolute alcohol, ab- 

 sorbed a much greater quantity of deutoxide of azote, and be- 

 came nearly black. A solution saturated with gas began to boil 

 at 100, evolving gas in great abundance, which, being collect- 

 ed in the pneumatic trough, proved to be pure deutoxide of 

 azote. The greater part of the gas was expelled before the al- 

 cohol rose to its boiling point, and after the solution was in the 

 state of ebullition for a few seconds gas ceased to rise, and the 

 alcoholic solution recovered its original colour, which was ge- 

 nerally a chocolate-brown, from the presence of a little bichloride 

 of iron. The quantity of gas evolved from a solution of one part 

 protochloride of iron in five parts absolute alcohol, amounted to 

 23 times the volume of the alcohol. 



I think it probable that the absorption of deutoxide of azote 

 by protochloride of iron, is analogous to the absorption of alco- 

 holic and aqueous vapours by the same body. For I find that 

 protochloride of iron absorbs alcohol-vapour as well as the va- 

 pour of water. The absorption of deutoxide of azote may de- 

 pend upon a tendency of chloride of iron to deliquesce in like 

 manner, in an atmosphere of that neutral oxide. At a very low 

 temperature, which it is perhaps out of our power to reach, 

 protochloride of iron would probably absorb this gas in sufficient 



