82 Historical Sketch of Improvements in [Aug. 



etherial vapour together with the carbonic acid and water result- 

 ing are precisely what that supposition would render necessary, 

 though Mr. Dalton does not appear himself to have seen the 

 obvious consequences of his own experiments. The specific 

 gravity of defiant gas is 0"9708, and that of vapour of water 

 0-625. Hence 



2 volumes defiant gas weigh 1'94]6 



1 volume vapour of water 0-6250 



Total = 2-5666 



Specific gravity of ether vapour . . = 2*5860 accord- 

 ing to the determination of Gay-Lussac. Now these two num- 

 bers are sufficiently near to warrant the conclusion that the 

 specific gravities of the two are in reality the same. According 

 to this view of the subject, the constituents of sulphuric cihex; 

 are as follows : 



Hydrogen 13-513 



Carbon 64-865 



Oxygen 21-622 



100-000 

 Or, which conies to the same thing, 



5 atoms hydrogen = 0-625 



4 atoms carbon = 3-000 



1 atom oxygen = 1-000 



4-625 



These conclusions differ very materially from those drawn by 

 Dalton ; yet whoever will take the trouble to examine his expe- 

 riments will find that they in reality lead to the above conclusion. 



2. Nitrous Ether. — ^When crystallized nitrate of lead is dis- 

 tilled, a yellow-coloured liquid is obtained, which is nitrous acid, 

 nearly, if not entirely, free from water. When absolute alcohol 

 and this acid are mixed together in small quantities at a time to 

 obviate as much as possible the violent heat which is evolved, 

 nitrous ether is formed at once ; and this is probably the best 

 way of forming that ether. (See Ann. de Chim. et de Phys. xii. 

 160.) Bouillon-Lagrange has proposed the following formula 

 for preparing this ether : 



Mix together equal parts of alcohol and nitric acid, and put 

 the mixture into a matrass. Saturate this mixture with nitrous 

 gas produced in the usual way. To the matrass are luted a set 

 of Woulfe's bottles, each halfway filled with a saturated solution 

 of common salt. The mixture gradually becomes hot, and in 

 about an hour and a half begins to boil. The Woulfe's bottles 

 must now be surrounded with a refrigerating mixture. The 

 boiling continues for half an hour. The whole nitric ether will 



