364 Royal Society : — 



mother-liquor yields on evaporation oily drops of sulphocyamde of 

 phenyle. 



The deportment of triethylphosphine with sulphocyanide of 

 phenyle induced me to investigate the action of this body upon several 

 other sulphocyanides. The substance which at once suggested itself 

 for examination was sulphocyanide of allyle, mustard-oil. This com- 

 pound reacts most powerfully with the phosphorus-base. On mixing 

 the two bodies, a powerful evolution of heat takes place, and the 

 mixture assumes a deep brown colour, but does not solidify cither on 

 cooling or on agitation. After several days' standing, however, very 

 large well-defined crystals are deposited which unfortunately are con- 

 taminated with the brown colouring matter of the solution. I have 

 not yet succeeded in getting them perfectly white, and have there- 

 fore not analysed them. Their formation, however, and their general 

 characters leave no doubt that they are the corresponding allyle- 

 compouud, 



(C.S.,)" ] 



(C,H,)(C,H,)J 



Triethylphosphine has remained in contact with sulphocyanide of 

 ethyle for more than a month without depositing any crystals. 

 A 2})'iori, however, the formation of an urea imder these circumstances 

 was doubtful, since sulphocyanide of ethyle differs from the corre- 

 sponding phenyle- and allyle-compounds, even in its deportment 

 with ammonia and the monamines. 



In concnsion, it deserves to be mentioned that there appears to 

 exist a similar series of arseniuretted ureas. Triethylarsine, when left 

 for some weeks in contact with sulphocyanide of phenyle, deposits 

 small crystals of a body which I believe to be the arsenic-compound 

 corresponding to the phosphorus-urea described in this paper. This 

 body requires a more minute examination. 



" On the Deflection of the Plumb-line in India caused by the 

 Attraction of the Himalaya Mountains." By the Venerable Arch- 

 deacon Pratt. 



" Note on Archdeacon's Pratt's paper on the Effect of Local 

 Attraction on the English Arc." By Captain Clarke, R.E. 



"On the Thermal Effects of Compressing Fluids." By J. P. 

 Joule, LL.D., F.R.S. 



The author in this paper gives an experimental demonstration of 



the correctness of Professor Thomson's formula, 6= ^p^, where d is 



the thermal effect, T the temperature from absolute zero, e the ex- 

 pansibility by heat, p the pressure, J the mechanical equivalent of 

 the thermal unit, and K the capacity for heat. The fluids experi- 

 mented on were water and oil, with the results tabulated below : — 



