Mr. A. H. Church on Parabensole. 415 



circonference et les cotes de toutes les figures inscrites. Cette 

 proportionalite me parait etre un postulatum bien plus naturel 

 que celui d'Euclide.' 



" It is remarkable that Legendi-e's effort to demonstrate the 

 thirty-second proposition by aid of a functional equation, is 

 nothing else at its root than an implicit statement of the very 

 axiom we contend for. Sir John Leslie's objections to the pro- 

 cess of Legendre were puerile ; the Edinburgh geometer wholly 

 forgot that constants might enter into the equation ; and that 

 while there are constants among angles, there are none among 

 lines. But these objections are not a whit more puerile than the 

 subsequent defences of the Frenchman's process by Baron Mau- 

 rice of Geneva." 



LVI. Note on Parabenzole, a new Hydrocarbon from Coal- 

 Naphtha. Bij Arthur H. Church, F.CS.* 



THE hydrocarbon which forms the subject of the present 

 communication first attracted my attention in 1855, in 

 the course of some researches on the benzole series f; and as I 

 coidd not identify it with any known member of that series, and 

 as its study seemed calculated to throw some light upon the dif- 

 ficult question of isomerism, I endeavoured to discover some 

 characteristics which might enable us to discriminate between 

 it and other hydrocarbons having the same centesimal compo- 

 sition. In the present paper I give an account of the facts which 

 I have already noticed ; I no longer withhold them, although my 

 observations will, I fear, be found very fragmentary; but the 

 pressure of other duties has hitherto prevented and is likely still 

 to prevent me from giving to the subject the attention it deserves. 

 In every sample of light coal-naphtha that I have as yet ex- 

 amined I have detected the presence of a hydi'ocarbon, alluded 

 to in my first memoir on the benzole series, and there stated to 

 boil at 97° C. This oil, hitherto I believe unrecognized, I have 

 obtained in considerable quantities with a perfectly constant 

 boiling-point of 97°'o : this boiling-point alone is sufficient to 

 distinguish the new substance from benzole, which, according to 

 my determination, boils steadily at 80°*8. The analysis of the 

 body boiling at 97°"5 gave exactly the per-centages requu-ed by 

 the formula C'^ H^, as the following numbers show : — 



I. '2115 grm. of oil gave '7155 grm. carbonic acid and •1465 

 grm. water. 



II. "2095 grm. of oil gave '709 grm. carbonic acid and "145 

 grm. water. 



* Communicated by the Author. 



t Phil. Mag. S. 4. vol. ix. pp. 256, 463. 



