408 NEW YORK STATE MUSEUM 



metallic iron and counts the formation of meteorites confirma- 

 tory of this conclusion. He also considers the specific gravity of 

 the earth, which is 5.5 against 2.5 for its surface rocks as render- 

 ing it certain that the interior contains substances heavier than 

 ordinary rocks. In these interior masses of metallic iron he 

 supposes more or less carbid of iron to exist as in meteorites. 

 Carbids of iron would also be formed by the descent of carbon- 

 ated water as in Berthelot's theory. Water infiltrating through 

 fissures in the crust would be turned into steam at the depth 

 supposed, and attacking the carbid of iron, would give rise to 

 the petroleum compounds. The steam already invoked exerts 

 pressure enough to force the petroleum vapors back toward the 

 surface till they would become condensed by cooling and would 

 be stored in all porous rocks capable of containing them. This 

 is by far the most widely known and powerfully supported theory 

 of the inorganic origin of bitumens. Mendeljeff expresses him- 

 self as satisfied with it and declares that petroleum is as truly 

 a product of chemical affinity as a veinstone or an ore. This 

 theory seems to promise a continual production and thus an un- 

 failing supply of oil and gas and is sure to be welcomed in ever} 7 

 field that is entering on its exploitation. 



In like manner chemists who have given but little attention to 

 the geologic facts connected with oil and gas further than that 

 they occur beneath the surface, finding a theory at hand explain- 

 ing the origin of these interesting substances on sound chemical 

 possibilities, have naturally turned to this explanation with 

 prejudice in its favor. Occasionally, also, a geologist has been 

 misled by it, but, little by little, as the far-fetched and highly 

 improbable assumptions of this theory have come to be consid- 

 ered and as a far simpler and more probable account of the 

 origin of bitumens is at hand, Mendeljeff's speculations have lost 

 standing with men of a practical turn, both chemists and geolo- 

 gists, till of late years no one has been found to champion it as 

 if he believed it. To geologists, indeed, it sounds like an echo 

 from the 18th century. It takes its place with the " cloud-capped 

 towers and gorgeous palaces " of the speculations of Werner's 

 time, 100 years ago. 



The latest vigorous defense of the theory in question was made 

 in 1889 by Mr William Anderson, at that time president of the 



