1869.] CHEMISTRY AND PHYSICS. 109 



Moreover, the cost of fluor-spar in many localities would be such 

 as to preclude its use. The experiments of Caron, however, 

 deserve notice as a partially successful attempt to solve a very 

 important problem in metallurgy. T. S. H. 



Natural InflaMxAiable Gases. — The recent investigations 

 by numerous chemists of the composition of petroleum from 

 various sources have shown it to consist in great part of 

 homologues of marsh gas, hydride of methyl, C H^ (C=12, 

 H=l), the most hydrogenated series of the hydro-carbons. 

 In addition to these, small portions of benzene and its 

 homologues, and of hydrocarbons of the ethylene or olefiant gas 

 series have been detected in the petroleums of certain regions. 

 Cahours and Pelouze have isolated from the products of the dis- 

 tillation of Pennsylvania petroleum not less than thirteen 

 homologues of marsh gas, having the general formula Cn H;i2+2, 

 in which the value of 71 increased from 4 to 15, and the boiling 

 point from 0° centigrade to 160°. The lower members of the 

 series in which n equals 2 and 3, and which are gases at the ordinary 

 temperature and pressure, were found by Ronalds in solution in 

 crude Pennsylvania petroleum. The denser and less volatile 

 liquids of petroleum, as well as the various solids included under 

 the name of paraiSne, appear to belong to the same series. 



Inflammable gases are well known to issue from the palaeozoic 

 rocks in many localities in the great Appalachian basin. Steiner 

 (Amer. Jour. Science [2] xxxiv, 46,) examined some years since 

 the gas from a well yielding salt water and petroleum, in the 

 carboniferous rocks of Alleghany county, Pennsylvania, and 

 found it to consist essentially of marsh gas, with a little carbonic 

 acid, and traces of oxygen and nitrogen, but could detect no olefiant 

 gas. My own examinations, many years since, of tlie inflammable 

 gases from the saline springs of Varennes and Caledonia in Canada, 

 which rise from Lower Silurian limestones, led to the same 

 result. 



Some two years since M. Felix Foucou, a French engineer, 

 visiting the oil regions of this country, was furnished with ex- 

 hausted tubes, in which he was enabled to collect the gases from 

 various localities. These gases were afterwards examined by Mr. 

 Fouque in the laboratory of the College of France, and the 

 results of the analyses, as well as the observations of Mr. Foucou, 

 are contained in the Comptes Rendus of the French Academy of 



