of several Gases into Liquids. 417 



liquid state. An important note was added to the paper by 

 the President, on the general application of the means used 

 in this case to the reduction of other gaseous bodies to the 

 liquid state ; and in illustration of the process, the production 

 of liquid muriatic acid was described. Sir Humphry Davy 

 did me tiie honour to request I would continue the experi- 

 ments, which I have done under his general direction, and 

 the following are some of the results already obtained : 



Sulphurotis Acid. 

 Mercury and concentrated sulphuric acid were sealed up 

 in a bent tube, and, being brought to one end, heat was care- 

 fully applied, whilst tie other end was preserved cool by wet 

 bibulous paper. Sulphurous acid gas was produced where 

 the heat acted, and was condensed by the sulphuric acid 

 above; but when the latter had become saturated, the sul- 

 phurous acid passed to the cold end of the tube, and was con- 

 densed into a liquid. When the whole tube was cold, if the 

 sulphurous acid were returned on to the mixture of sulphuric 

 acid and sulphate of mercury, a portion was reabsorbed, but 

 the rest remained on it without mixing. 



Liquid sulphurous acid is very limpid and colourless, and 

 highly fluid. Its refractive power, obtained by comparing it 

 in water and other media with water contained in a similar 

 tube, appeared to be nearly equal to that of water. It does 

 not solidify or become adhesive at a temperature of 0° F. 

 When a tube containing it was opened, the contents did not 

 rush out as with explosion, but a portion of the liquid evapo- 

 rated rapidly, cooling another portion so much as to leave it 

 in the fluid" state at conmion barometric pressure. It was 

 however rapidly dissipated, not producing visible fumes, but 

 producing the odour of pure sulplmrous acid, and leaving the 

 tube quite dry. A portion 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 xuiexceptionable manner that the fluid 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 condensing syringe, 

 till there were three or four atmospheres ; the lube remained 

 perlecdy clear and dry; but on cooling one end to 0°, die fluid 

 sulphurous acid condensed, and in all its characters was like 

 that prepared by the i()rmer process. 



A small gaiig(! was attached to a tube in which sulphurous 

 Vol. 62. No. 308. Dec. 1823. 3 G acid 



