339 



tained in boghead naphtha. In it he gives the results of his experi- 

 ments on that portion of the fluid which resists the action of mono- 

 hydrated nitric and sulphuric acids. He had previously stated the 

 fact of his having obtained a substance possessing the composition 

 and vapour-density of butyl*, and had expressed a belief that he 

 should succeed in isolating not only that radical, but also propyl, 

 amyl, and caproyl. The composition of the radicals varies so little, 

 that to determine the boiling-points it was necessary to take the 

 density of the vapour of all those fractions which distilled anywhere 

 near their known boiling-points ; and in each case he regarded that 

 fraction which gave the nearest result as representing the boiling- 

 point of the radical as obtained from the source mentioned. 



Propyl presented itself under the form of a colourless, very mobile 

 fluid, having a pleasant odour, and boiling at 68 C. At lb it had 

 the very low density of 0*6745. Combustion gave results agreeing 

 closely with the formula 



=4 vols., 



confirmed by a determination of the density of its vapour by Gay- 

 Lussac's method, which gave 2*96, theory requiring 2'97. Propyl 

 had not been previously obtained. 



Butyl from the Torbane-hill mineral distils at 119, and has a 

 density of 0'6945 at 18; its analysis coincided with the formula 



OH". 

 The vapour-density was found to be 3*88, theory requiring 3*94. 



Amyl distilled at 159, and had a density of 0- 7365 at 18. On 

 analysis, numbers were obtained agreeing perfectly with the formula 



C 20 H 22 . 

 The vapour-density was found to be 4*93 ; theory requires 4*9 1. 



Caproyl boiled at 202 ; its density at 18 was 07568. The 

 results of analysis accorded with the expression 



C 24 H 26 , 



which indicates a vapour-density of 5'87, while experiment yielded 

 5-83. 



The experiments detailed in the paper appear to demonstrate the 



* Proceedings of the Royal Society, vol. viii. p. 119. 

 VOL. VIII. 2 D 



