OF GASEOUS BODIES. 121 



When 2 atoms of sulphur 32, combine with 1 

 atom of hydrogen, the resulting compound is 

 a brownish yellow, and dense liquid, (specific 

 gravity 1-769), somewhat acid, of an oily and 

 tenacious consistence. If it be submitted to very 

 low temperatures, its specific gravity and cohesion 

 are still farther augmented, when it becomes an 

 exceedingly firm solid, like butter, tallow, and 

 innumerable other fluids and semifluids under the 

 same circumstances. When an atom of sulphur 

 16, combines with 2 atoms of oxygen 16 ; or when 

 sulphur vapour combines with oxygen, the elas- 

 ticity of the latter is nearly destroyed ; while the 

 atoms of sulphur are removed farther from each 

 other, and acquire a degree of elasticity at the 

 expense of the oxygen : for the specific gravity of 

 the sulphurous acid thus formed is only 2' 222, 

 which is just i of 6'666, that of the sulphur vapour, 

 in agreement with the law of multiples, which may 

 be traced in all the contractions and expansions 

 that gaseous bodies undergo during combination 

 and decomposition. 



According to the experiments of Faraday, sul- 

 phurous acid may be liquefied by a pressure equal 

 to 2 atmospheres, at the temperature of 45 ; and 

 by cold without pressure, according to the ex- 

 periments of Bussy and others. It must be ob- 

 served, however, that during the combinations of 

 oxygen and sulphur, a portion of caloric is given 

 out, as in the union of oxygen and hydrogen to 



