S18 Dr Bischof s Examination of Three Itiflammahle Gases 



of liquid potash, and this gas was subtracted from the residue. 

 The following is the detail of two experiments. 



Pit-gas free from carbonic acid gas, . 154. y. 142. v. 



Chlorine gas added, . . . 136. v. 137. v. 



After washing the gaseous mixture with liquid potash, 156.6 v. 141. v. 

 136 volumes of chlorine, however, contained of at- 



leric air, . . . 8.35 4.86 



Hence the true residue of pit-gas after treatment with 



chlorine was .... 148.16 136.64 



Absorption .... 6.86 6.86 



If we regard the gas absorbed as olefiant gas, its quantity 

 amounts to .... 0.038 0.038 



The original quantity of olefiant gas must have been much 

 greater before the pit-gas came in contact, in a variety of 

 ways, with water in the gas-canals, because it is more abun- 

 dantly absorbed by water than is carburetted hydrogen gas. 



Two other experiments on pit-gas which had been collected 

 a day later in the JFellesweiler mine, afforded, by means of 

 chlorine, an absorption of 0.028 and 0.037 volumes. 



An examination of pit-gas for olefiant gas by means of su- 

 perchloride of antimony over mercury, yielded less satisfactory 

 results, and I shall not therefore communicate any of the details. 



§ 4. Pit-gas and cldorine exposed to the light. 

 ^ s I do not know that a perfectly pure inflammable pit-gas 

 has ever before been subjected to this experiment, I took ad- 

 vantage of the opportunity afforded me, to make the trial with 

 the almost pure carburetted hydrogen from the Wellesweiler 

 mine.* To 158 volumes of pit-gas, previously washed with 

 liquid potash, were added, over water, about double the volume 

 of chlorine, and exposed for five hours to the diffused day-light. 

 The volume was diminished to 94, After having been agi- 



♦ Gay-Lussac and Thenard (Eecherclies Pliysico-Chimiques, t. 2, p. 191) 

 Iiave only performed experiments with gas " provenant de la decomposition 

 de Palcohol, ou d'uno huile, a travcrs un tube rouge de feu, ou enfin avec les 

 gaz inflammables compose's qu'on obtient en distillant une substance vege- 

 tale ou animale quelconque. Tonjours il y a eu d' action instantan^e a la 

 lumi^re solaire, et en m^me temps qu'il y a cu detonation riolcnte dans ce 

 cas, il y a qu un depot sovvcnt ti<s covsidaxdk de charbon." 



