1824.] Liquefaction of Chlorine and other Gases. 85 



pass by it to the inside of the gage. In estimating the number 

 of atmospheres, one has always been subtracted for the air left 

 in the tube. 



The specific gravity of sulphuretted hydrogen appeared to 

 be 0-9. 



Carbonic Acid. 



The materials used in the production of carbonic acid, were 

 carbonate of ammonia and concentrated sulphuric acid ; the 

 manipulation was like that described for sulphuretted hydrogen. 

 Much stronger tubes are however required for carbonic acid than 

 for anv of the former substances, and there is none which has 

 produced so many or more powerful explosions. Tubes which 

 have held fluid carbonic acid well for two or three weeks toge- 

 ther, have, upon some increase in the warmth of the weather, 

 spontaneously exploded with great violence; and the precau- 

 tions of glass masks, goggles, &c. which are at all times neces- 

 sary in pursuing these experiments, are particularly so with car- 

 bonic acid. 



Carbonic acid is a limpid colourless body, extremely fluid, 

 and floating upon the other contents of the tube. It distils 

 readily and rapidly at the difference of temperature between 32° 

 and 0°. Its refractive power is much less than that of water. 

 No diminution of temperature to which I have been able to sub- 

 mit it, has altered its appearance. In endeavouring to open the 

 tubes atone end, they have uniformly burst into fragments, with 

 powerful explosions. By inclosing a gage in a tube in which 

 fluid carbonic acid was afterwards produced, it was found that 

 its vapour exerted a pressure of 36 atmospheres at a temperature 

 of 32°. 



Euchlorine. 



Fluid euchlorine was obtained by inclosing chlorate of potash 

 and sulphuric acid in a tube, and leaving them to act on each 

 other for 24 hours. In that time there had been much action, 

 the mixture was of a dark reddish brown, and the atmosphere of 

 a bright yellow colour. The mixture was then heated up to 

 100°, and the unoccupied end of the tube cooled to 0°; by degrees 

 the mixture lost its dark colour, and a very fluid ethereal looking 

 substance condensed. It was not miscible with a small portion 

 of the sulphuric acid which lay beneath it ; but when returned 

 on to the mass of salt and acid, it was gradually absorbed, 

 rendering the mixture of a much deeper colour even than itself. 



Euchlorine thus obtained is a very fluid transparent sub- 

 stance, of a deep yellow colour. A tube containing a portion of 

 it in the clean end, was opened at the opposite extremity ; there 

 was a rush of euchlorine vapour, but the salt plugged up the 

 aperture : while clearing this away, the whole tube burst with a 

 violent explosion, except the small end in a cloth in my hand, 



