189S.] PECKHAM — THE GENESIS OF BITUMENS. 121 



variety and are uniformly more difficult to refine into commercial 

 articles than the bitumens obtained from older formations/ 



It is proper to mention in this connection three classes of inves- 

 tigations that have been made on a commercial scale. The first 

 was made about 1860-65, by Cyrus M. Warren, and consisted in 

 distilling destructively the lime soap made from menhaden (fish) 

 oil. The products of this distillation were refined into illuminating 

 oil, in all respects identical with coal oil and refined petroleum ; 

 and they were also proved by an elaborate research to contain the 

 same constituent hydrocarbons. Quite recently, Prof. Karl Eng- 

 ler, has repeated these experiments with the addition of pressure and 

 steam during distillation. Warren's results were confirmed. Still 

 more recently, Dr. S. P. Sadtler has discovered that the vapors 

 escaping from linseed oil while being boiled furnish, when con- 

 densed, a petroleum-like liquid, which upon examination was found 

 to consist of hydrocarbons identical with those found in Pennsyl- 

 vania petroleum. It is an honor to American science that these 

 results, valuable and interesting alike to science and technology, 

 were obtained by American investigators." 



The general conclusion from technology appears to be, that for 

 commercial purposes, crude bitumens and the products of their dis- 

 tillation may be duplicated by products of the destructive distilla- 

 tion of pyroschists, wood, coal, peat and a great variety of animal 

 and vegetable substances. 



13. It would be entirely unnecessary for my present purpose to 

 notice in detail all the researches that have been undertaken upon 

 bitumen, in all its various forms, since de Saussure published his 

 paper on the Naphtha of Amiano, in 181 7. It is sufficient to indi- 

 cate along what lines the investigations have proceeded and in what 

 manner the results have been interpreted. The earliest investiga- 



1 Boverton Redwood, Petroleum, etc., London, Charles Griffin & Co., 1896, 

 ii. S. F. Peckham, Prog. Am. Phil. Soc, x, 445. Repts. 10th Census ^ U.S., x. 

 « Petroleum," Am. Jour. Sci. (3), xlviii, 250 and 389, 1, 33. Science xxiii, 

 74. Jour Frank. Institute, Nov., 1895. S. P. Sadtler, Am. Jour. Pharm., 

 Sept., 1896. C. F. Mabery, Joitr. Frank. Institute, cxxxix, 401. Proc. Am. 

 Acad., n. s., xxiii. Am. Chem. Jour., xix, 243, 374, 419,796. B. Silliman, Jr., 

 Am. Jotir. Sci. (ii), (xliii,) 242. Chein. News, xvii, 257. Bui. Soc. C/iem. de 

 Paris, 1868, p. 77. 



2C. M. Warren and F. H. Storer, Me?n. Am. Acad.,n. s., ix, 177. Karl Eng- 

 ler, Berichte der Deut. Chem. Gesellschaft, 1888, xxi, 1816, xxii, 592. Dingier, 

 Poly. Jour., 18S9, p. 271. S. P. Sadtler, Am. Jour. Phar., Sept., 1896. 



