VOL. LXXX.] PHILOSOPHICAL TRANSACTIONS. 635 



2. That no fixed air is formed during the separation of the lighter air from 

 the heavy inflammable air. Here it should be observed, that if the constitution 

 of the heavy inflammable air depended on the union of the light inflammable 

 and fixed airs, as some have supposed, we should certainly discover the fixed air, 

 when the other part was separated from it. Or, should it be conjectured, that 

 the light inflammable air is separated from water suspended in the heavy inflam- 

 mable air, in that case, would not fixed air be formed from the other constituent 

 part of the water uniting with the heavy inflammable air, in consequence of 

 the repeated electrical shocks ? 



3. That the electrical shock separated a substance from the heavy inflammable 

 air, which has some leading characters of an alkali. When inflammable air is 

 decomposed by sulphur, or when hepatic air is made from charcoal and sulphur, 

 we have the same appearance of an alkali. That this is the volatile alkali is evi- 

 dent from its evaporation, when hepatic air is made from sulphur and charcoal. 



4. That the heavy inflammable air, through which the spark has been re- 

 peatedly passed, when burnt with any proportion of dephlogisticated air, does 

 not produce so much fixed air, as the same quantity of inflammable air not elec- 

 trified. Hence it is evident, that a part of the air is actually decomposed by the 

 spark. Hence also we may infer, that the decomposed air is not resolved into 

 light inflammable air and charcoal, of which some chemists have supposed it to 

 consist, because the charcoal would combine with dephlogisticated air after its 

 separation from light inflammable air, and we should not have such a defect of 

 fixed air. 



5. That the residues, after inflaming the decomposed air, are generally 

 greater than those from the air in its natural state, or than can be accounted 

 for from the mixture of the heavy inflammable and dephlogisticated airs. This 

 aflfords a strong presumption, that phlogisticated air is extricated from the de- 

 composed heavy inflammable air in a separate state, besides what enters into the 

 volatile alkali, which is formed at the same time. If light inflammable air only 

 were disengaged during the decomposition, the residues would certainly not be 

 greater after inflammation with a sufficient quantity of dephlogisticated air ; on. 

 the contrary, if the inflammable air were increased in proportion in the mix- 

 ture, the combustion would be more complete, and the residues less. 



Having observed, that sulphur readily combines with light inflammable air, 

 if presented to each other at the instant that the inflammable air is detached 

 from other bodies, before its particles have receded from each other, and that 

 hepatic air is generally formed in this manner, he introduced some sulphur and 

 heavy inflammable air into a glass retort, first filled with, and inverted in quick- 

 Tsilver, and applied a sufficient heat to melt it. The heat was continued till the 

 sulphur was sublimed. The melted sulphur soon acquired a dark reddish co- 



4m 2 



