124 On the Liquefaction of Gases. [1824. 



has passed the Cagniard de la Tour point or not is not known, 

 and therefore it cannot well be anticipated whether the coming 

 on of that state sooner or later with particular bodies will in- 

 fluence them in relation to the more general law referred to 

 above. 



The law already suggested gives great encouragement to the 

 continuance of those efforts which are directed to the conden- 

 sation of oxygen, hydrogen and nitrogen, by the attainment 

 and application of lower temperatures than those yet applied. 

 If to reduce carbonic acid from the pressure of two atmospheres 

 to that of one, we require to abstract only about half the num- 

 ber of degrees that is necessary to produce the same effect with 

 sulphurous acid, it is to be expected that a far less abstraction 

 will suffice to produce the same effect with nitrogen or hydro- 

 gen, so that further diminution of temperature and improved 

 apparatus for pressure may very well be expected to give us 

 these bodies in the liquid or solid state. 



Royallnstitution, Feb. 19, 1845. 



Historical Statement respecting the Liquefaction of Gases *. 



I WAS not aware at the time when I first observed the liquefac- 

 tion of chlorine gas f , nor until very lately, that any of the 

 class of bodies called gases, had been reduced into the fluid 

 form; but having during the last few weeks sought for in- 

 stances where such results might have been afforded without 

 the knowledge of the experimenter, I was surprised to find 

 several recorded cases. I have thought it right therefore to 

 bring these cases together, and only justice to endeavour to 

 secure for them a more general attention than they appear as 

 yet to have gained. I shall notice in chronological order, the 

 fruitless, as well as the successful attempts, and those which 

 probably occurred without being observed, as well as those 

 which were remarked and described as such. 



Carbonic Acid, $c. The ( Philosophical Transactions ' for 

 1797 contain, p. 222, an account of experiments made by 

 Count Rumford, to determine the force of fired gunpowder. 



* Quarterly Journal of Science, xvi. 229. 



f Philosophical Transactions, 1823, pp. 160, 189 or page 85. 



