several gases into liquids. 
1 95 
Nitrous oxide. 
Some nitrate of ammonia, previously made as dry as could 
be by partial decomposition, by heat in the air, was sealed 
up in a bent tube, and then heated in one end, the other be- 
ing preserved cool. By repeating the distillation once or 
twice in this way, it was found, on after-examination, that 
very little of the salt remained undecomposed. The process 
requires care. I have had many explosions occur with very 
strong tubes, and at considerable risk. 
When the tube is cooled, it is found to contain two fluids, 
and a very compressed atmosphere. The heavier fluid on ex- 
amination proved to be water, with a little acid and nitrous 
oxide in solution ; the other was nitrous oxide. It appears in 
a very liquid, limpid, colourless state ; and so volatile that the 
warmth of the hand generally makes it disappear in vapour. 
The application of ice and salt condenses abundance of it 
into the liquid state again. It boils readily by the difference 
of temperature between 50° and o°. It does not appear to 
have any tendency to solidify at — 1 o°. Its refractive power is 
very much less than that of water, and less than any fluid 
that has yet been obtained in these experiments, or than any 
known fluid. A tube being opened in the air, the nitrous 
oxide immediately burst into vapour. Another tube opened 
under water, and the vapour collected and examined, it 
proved to be nitrous oxide gas. A gage being introduced 
into a tube, in which liquid nitrous oxide was afterwards 
produced, gave the pressure of its vapour as equal to above 
50 atmospheres at 45° 
