Condensation of Several Gases into Liquids. 353 



thlorine, JYitrous Oxide, Cyanogen, Ammonia, Muriatic 

 jicid and Chlorine. Although these experiments are scarce- 

 ly susceptible of abridgement, yet we are compelled, by 

 want of room, to leave out the few parts of the memoir 

 which are less essential than the rest. 



" Sulphurous Acid. — Mercury and concentrated sul- 

 phuric acid were sealed up in a bent tube, and being brought 

 to one end. heat was carefully applied whilst the other end 

 was preserved cool by wet bibulous paper. Sulphurous 

 acid gas was produced where the heat acted and was con ■ 

 dens^d by the sulphuric acid above; but when the latter 

 had become saturated, the sulphurous acid passed to the 

 cold end of the tube, and was condensed into a liquid- 

 When the whole tube was cold, if the sulphurous acid was 

 returned on to the mixture of sulphuric acid and sulphate 

 of mercury, a portion was reabsorbed, but the rest remain- 

 ed on it without mixing. 



'• Liquid sulphurous acid is very limpid and colourless, 

 and highly fluid. Its refractive power, obtained by com- 

 paring it in water and other media, with water contained 

 in a, similar tube, appeared to be nearly equal to that of wa- 

 ter. It does not solidify or become adhesive at a tempe- 

 rature of 0° F. When a tube containing it was opened, 

 the contents did not rush out as with explosion, but a por- 

 tion of the liquid evaporated rapidly, cooling another por- 

 tion so much as to leave it in the fluid state at common ba- 

 rometric pressure. It was however rapidly dissipated, not 

 producing visible fumes, but producing the odour of pure 

 sulphurous acid, and leaving tlie tube quite dry. A por- 

 tion of the vapour of the fluid received over a mercurial 

 bath, and examined, proved to be sulphurous acid gas. A 

 piece of ice dropped into the fluid instantly made it boil, 

 from the heat communicated by it. 



" To prove in an unexceptionable manner that the flui(J 

 was pure sulphurous acid, some sulphurous acid gas was 

 carefully prepared over mercury, and a long tube perfectly 

 dry, and closed at one end, being exhausted, was filled 

 with it; more sulphurous acid was then thrown in by a con- 

 densing syringe, till there were three or four atmospheres ; 

 the tube remained perfectly clear and dry, but> on cooling 

 one end to 0°, the fluid sulphurous acid condensed, and is 



Vol. Vll.— No. 2. 45 



