CYRUS MOORS WARREN. 895 



in New York City, and in several other of the larger cities of this 

 country, aud had made contracts for long terms of years with many of 

 the largest gas-works, which gave them assured control of all the tar 

 which might be produced. Hence, when the auilin dyes came into 

 use, and a great demand arose for those portions of coal-tar naphtha 

 from which these dyes were made, the Warrens were peculiarly fa- 

 vorably situated for producing the naphtha, and gained large profits 

 by selling it. 



Nothing could have been more natural than that the scientific mem- 

 ber of the firm should turn his attention to the question how best to 

 obtain these volatile products ; and nothing marks the great inventive 

 power of the man more clearly than the masterly way in which he 

 solved this highly iutricate problem. His process of "fractional con- 

 densation," as published in 1864 in the Memoirs of this Academy, 

 is admirable alike as a means of scientific research and as a techno- 

 logical method. This memoir, with its explanatory diagrams, was 

 widely copied in scientific journals, and an expert travelling in Europe 

 in 1870 found the process in common use there in the distilleries of 

 tar. In some instances the managers of these works knew that they 

 were using Warren's invention, while others professed ignorance as to 

 its origin, while freely admitting its excellence. 



By means of this apparatus Warren dissected, so to say, in a most 

 thorough and exhaustive manner the more volatile portions of the tars 

 and oils which are obtained by the distillation of coal and of wood, as 

 well as the naphthas of petroleum ; and in so doing he solved well- 

 nigh completely a chemical problem which had been regarded as one 

 of the most intricate of the time. He claimed with justice for his 

 apparatus that it enabled the chemist, occupied with the study of mix- 

 tures of volatile, non-decomposable liquids, to prove the negative as 

 well as the positive, since by means of it it is easy to separate and 

 obtain in a state of almost absolute purity the several components of 

 the mixtures, and at the same time to prove that the mixtures con- 

 tained no other substances than those actually isolated. 



One important result of these researches was the wholly unlooked for 

 discovery that the more volatile portions of Pennsylvanian petroleum 

 contain two distinct series of homologous hydrocarbons (C„H 2n+2 ), 

 which run parallel one with the other. The boiling-points of the 

 contiguous members of either series differ by 30° C. But while the 

 several members of the first series boil at 0°, 30°, 60°, 90°, etc., 

 the members of the other series boil at 8°, 38°, 68°, 98°, and so on. 

 That is to say, the members of the two series boil at intermediate 



