354- Mr. Reuben Phillips on the Elasticity of Gases. 



voltaic current*. I should perhaps except olefiant gas, which 

 appears to give rise to a continuous though extremely feeble 

 current; and the vapours of bromine and iodine, were they 

 less soluble, would probably also be found efficient as electro- 

 negative gases. 



[To be continued.] 



LI. Some Remarks on the Elasticity of Gases. 

 By Reuben Phillips. 



To Richard Taylor, Esq. 

 Sir, 

 T^HE pressure exercised by a gaseous volume on surround- 

 ing matter, as measured by its pressure on a small square 

 unit, has been found to vary as the volume, or that the vo- 

 lume, plus the pressure on the square unit, is always equal, 

 the ponderal quantity of gaseous matter being of course con- 

 stant. Now, if a gaseous volume may be represented by the 

 symbol (vy)% in which y is the distance between the atomic 

 centres, and v the number of times y is contained in one side 



of the cube (vy) s , then Mp- = —^ — -^- 9 z being any posi- 

 tive or negative quantity, but so taken as not to render the 

 fraction 0, or OC; therefore the gaseous volume varies as the 

 cube of y; but the pressure also varies as the volume, and 

 therefore as y 3 . If the pressure be assumed to proceed from 

 the mutual repulsion of the gaseous particles, it is hereby 

 shown that such repulsion varies as the cube of the distance 

 between the atomic centres. This seems to be an exception 

 to the general law, whereby forces emanating from a centre 

 vary as the square of their distance from that centre, which 

 appears to point out as a fact, that gaseous repulsion does not 

 solely proceed from centres. 



I remain, Sir, 

 Your most obedient Servant, 

 Monmouth Street, Topsham. REUBEN Phillips. 



LI I. On some new Species of Biliary and Intestinal Concre- 

 tions. By Thomas Taylor, Esq. 

 To Richard Taylor, Esq. 

 Dear Sir, 

 CEVERAL statements having appeared in the continental 

 *** journals with regard to the composition of some new 

 species of biliary and intestinal concretions, I have received 

 permission from the Museum Committee of the Royal College 

 of Surgeons to state, that in the second and third parts of the 

 * See Postscript. 



