Peoceedings of the Polytechnic Associatiox. 905 



distillation of schist oils at an elevated temperature, only in a less 

 striking manner than is the case with petroleum. Unhappily, 

 my choice was very limited, and I was specially in want of the 

 distillates from the crude heavy oils for the production of lubrica- 

 tors, otherwise the decomposition of the schist oils could have been 

 more precisely determined. 



Ujjon this decomposition a j>rocess could Jje founded for changing 

 the heavy petroleum oils hy a high heat {at least partially) into illu- 

 minating oils, as Mr. JBreitenlohner, of Chlumetz, Bohemia, has 

 already done with heavy peat oils.* 



This principle has already found application in the refinery of 

 Messrs. Cogniet, Marechal & Co., as yet, however, on a very limited 

 scale. 



From the foregoing table we notice a diminution of the inflamma- 

 bility with the increase of density, in case no decomposition has yet 

 taken place by too elevated a temperature ; but even an approximate 

 relation between these two points is, however, not perceivable. If 

 the greater or less inclination of the oils to inflame was simply 

 dependent upon the boiling points of the single fractions, which would 

 represent more or less constant mixtures of hydro-carbons of the 

 series ' C'^" H~" X 2, as isolated by Cahours, Pelousef and Schor- 

 lemnier :j: then a fixed relation between the inflammal)ility and 

 density would be the necessary consequence ; this relation is, how- 

 ever, very probably concealed by a diflerent degree of absorption by 

 the various " fractions " of the highly inflammable gases, which are 

 met with in the oils. 



A fraction which holds a certain quantity of gas, possesses also a 

 corresponding inclination to inflame. 



For making the crude petroleum applicable and perfectly safe for 

 tlie heating of steam-boilers, it would be necessary to separate all the 

 oils until the density of 0.783 is reached, and then to free it from the 

 absorbed gases. Though oils may yet be present, which are inflam- 

 mable from 1.22 to 1.67 degrees F., their percentage is so small that 

 the fluid will bear a heat of 176 to 212 degrees F., without there being 

 any danger of explosion. The oil below the density of 0.783 could be 

 sold partly as kerosene, partly as essence for the so-called magic lamp. 



After some discussion on the paper of Dr. Ott, the association 

 adjom-ned. 



* Polytechnic Journal of Dingier, CLXVII, page 378. 



+ Pelouse, Comptes Reiides, Vol. LVI., page 505 ; Vol. LVII., page 62. 



X Schorlemmer, Chemical News, 1863, page 157. 



