224 PHILOSOPHICAL TRANSACTION'S. £ANNO 1797. 



some experienced chemists have met with, in their attempts to expand the carbo- 

 nated hydrogenous gas by electricity. Gas which is thus vitiated, becomes how- 

 ever capable of expansion, after exposure to the sulphure of pot-ash. 



Exper. 3. Carbonated hydrogen 340 measures were exploded with the proper 

 proportion of oxygenous gas. The carbonic acid produced amounted to 380 mea- 

 sures, and the residue of azotic gas was 20 measures. — Exper. 4. The same quan- 

 tity, when expanded to 690, gave on combustion 380 measures of carbonic acid, 

 and 19.8 of azotic gas. — Exper. 5. 315 measures of carbonated hydrogen yielded 

 359 measures of carbonic acid, and 18.5 measures of azote. — Exper. 6. The same 

 quantity, after expansion to 000, afforded the same products of carbonic acid and 

 azotic gases. — Exper. 7 and 8. As much carbonic acid was obtained by the com- 

 bustion of 408 measures of carbonated hydrogenous gas, expanded from 200, as 

 from 200 measures of the non-electric fired gas; and the residues of azotic gas 

 were the same in both cases. 



It is unnecessary to state the particulars of several other experiments, similar to 

 those above related, which were attended with the same results. They sufficiently 

 prove that the action of the electric spark, when passed through carbonated hy- 

 drogenous gas, is not exerted in the decomposition of carbon; for the same quantity 

 of this substance is found after as before electrization. Even granting that char- 

 coal is a compound, the constituents of which are held together by a very forcible 

 affinity, it does not appear likely that the agency of the electric shock, which 

 seems, in this instance, analogous to that of caloric, should effect its decomposition 

 under the circumstances of these experiments. For it is a known property of char- 

 coal to decompose water, when aided by a high temperature; and its union with 

 oxygen is a much more probable event, when this body is present, than a separa- 

 tion into its constituent principles. As an argument also, that water is the source 

 of the light inflammable air in this process, it may be observed, that the dilatation 

 in Dr. Austin's experiments could never be carried much farther than twice the 

 original bulk of the gas*. This fact evidently implies that the expansion ceased 

 only in consequence of the entire destruction of the matter, whose decomposition 

 afforded the light inflammable air, and this substance could not be carbon, because 

 Dr. Austin admits that a large portion, and I have shown that the whole of it still 

 remains unaltered. 



If the dilatation of the carbonated hydrogenous gas arose from the decomposition 

 of water, the effect should cease when this fluid is previously abstracted. To as- 

 certain whether this consequence would really follow, I exposed a portion of the 

 gas, for several days before electrization, to dry caustic alkali. On attempting its 



* " After the inflammable air has been expanded to about double its original bulk/' says Dr. Austin, 

 '• I do not find that it increases further by continuing the shocks. Conceiving that the progress of the 

 decomposition was impeded by the mixture of the other airs with the heavy inflammable, I passed the 

 spark through a mixture of the heavy inflammable air and light inflammable; but the expansion suc- 

 ceeded nearly as well as when the heavy inflammable was electrified alone." Phil. Trans, vol. 80, 

 p. 52.— Orig. 



