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Fhi/sical and Chemical Examination of Three Inflammable 

 Gases which are evolved in Coal-Mines, By Dr Gustav 

 BiscnoF, Professor of Chemistry in the University of 

 Bonn. Communicated by the Author. 



The financial department of the Prussian ministry com- 

 missioned me to investigate the inflammable gas which forms in 

 the Prussian coal-mines what is termed Fire-damp, and to make 

 experiments in explosive mixtures with Davy's safety- lamp. 

 Chemists, from investigations made in England, regard this 

 inflammable gas merely as carburetted hydrogen, and even, 

 after marsh gas, as the purest carburetted hydrogen gas that 

 can be obtained ; but the analyses of the gases from the 

 English coal-mines by no means justify the assumption, that 

 the inflammable gases from other coal mines are invariably of 

 the same nature. 



It is but rarely that a good opportunity presents itself in 

 mines, of collecting this gas in a perfectly pure condition. If 

 the mines in which it is evolved be damp, its evolution is 

 rendered evident by a peculiar sound which may be exactly 

 compared to the noise caused by the movement of a number 

 of crabs in a basket. We also perceive, on the floor or the 

 roof of the galleries, bubbles, which, by bursting, cause this 

 noise, and which can often be ignited by the lamp. Should, 

 however, the mines be perfectly dry, the evolution of this gas 

 can only be ascertained by the formation of fire-damp. Be- 

 sides these evolutions, extending over a greater or smaller 

 extent, by means of which the fire damp is produced at such 

 places, when no strong current of air exists, there are also 

 particular points where the inflammable gas flows out in 

 greater or less abundance, from fissures in the coal-strata or 

 neighbouring rock. Such places, which are termed blowers 

 (blaserj, are, however, but rare in our mines. It is evident 

 that it is such blowers alone which admit of the collection of 

 a perfectly pm*e gas. 



In the year 1837, while visiting some of the coal-mines in 

 the vicinity of Saarbriicken, I found a gaseous exhalation of 

 thia description issuing from a fissure in sandstoae of the 



