Notices of Memoirs — 0. C. D. Moss — On Petroleum. 507 



strata is next dealt with, and extracts in proof thereof are given 

 from several writers. In illustration of volcanic action on carbonate 

 of lime, a sulphur mine in Spain, within a short distance of an 

 extinct volcano (with which the author is well acquainted), is 

 mentioned. That petroleum is not far off is indicated by a perpetual 

 gas flame in a neighbouring chapel and other symptoms ; and, these 

 circumstances having attracted his attention, he observed that Dr. 

 Christoph Bishop records in his writings that he had produced 

 sulphur in his own laboratory by passing hot volcanic gases through, 

 chalk, which fact further led the author to remark that, in addition 

 to sulphur, ethylene, and all its homologues (CnHjn), which are the 

 oils predominating at Baku, would be produced by treating — 



2, 3, 4, 5 equiv. of limestone (carbonate of lime) with 



2, 3, 4, 5 equiv. of sulphurous acid (SO^) and 



4, 6, 8, 10 equiv. of sulphuretted hydrogen (H-S) ; 



and that marsh gas and its homologues, which are the oils pre- 

 dominating in Pennsylvania, would be produced by treating — 



1, 2, 3, 4, 5 equiv. of carbonate of lime, with 



1, 2, 3, 4, 5 equiv. of sulphurous acid, and 



3, 5, 7, 9, 11 equiv. of sulphuretted hydrogen. 



Thus, we find that 



Carbonate of lime 2Ca2C03 \ { 2(Ca2SO*.H20) (gypsum) 



Sulphurous acid 280- \ yield } 48 (sulphur) 



and sulphuretted hydrogen 4H^S ) ( C-H*, which is ethylene, 



and 



Carbonate of lime Ca^CO^ | ( Ca^SO^.H^O (gypsum) 



Sulphurous acid 80^ ^ yield < 38 (sulphur) 



and sulphuretted hydrogen SH'^S ; ' CH*, which is marsh gas. 



These and all their homologues would be produced in nature by the 

 action of volcanic gases on limestone. 



But much the most abundant of the volcanic gases appear (at any 

 rate at the surface) as steam, and petroleum appears to have been 

 more usually produced without sulphurous acid and with part of 

 the sulphuretted hydrogen H^S replaced by H^O (steam), or H^O* 

 (peroxide of hydrogen), which is the product that results from the 

 combination of sulphuretted hydrogen and sulphurous acid (H^S + SO^ 

 =H20^+2S). Thus 



Ca^CO^ ) ( Ca^SO^.H^O (gypsum) 



H^S [ yield and 



2H20 ) [ CB.\ marsh gas 



and 



2Ca-C0=' ) ( 2Ca2SO*.H20 (gypsum) 



2H-'S \ yield ( and 



2H202 ) I C^HS or ethylene. 



Four tables are given at the end of the paper, showing the 

 formula for the homologues of ethylene and marsh gas resulting 

 from the increase in regular gradation of the same constituents. 



It is explained that these effects must have occurred, not at 

 periods of acute volcanic eruptions, but in conditions which may be 

 and have been observed at the present time wherever thei'e are 

 active solfataras, or fumaroles, at work. Descriptions of the action 

 of solfataras by the late Sir Kichard Burton and a British Consul ia 



