[■ 



(56). 



196 Drs. Ramsay and Young on 



values for y — and y = b. Lastly, by (1), with (49), we 

 have 



where 



\nu ay m / j 



Our six arbitrary constants, H, K, L, M, P, Q, clearly 

 allow us to give any prescribed values to each of ^, V, w, 

 for y = and for y = b. Thus the completion of the realized 

 problem with real data of arbitrary functions, as described in 

 § 37, becomes a mere affair of routine. 



40. Now remark that the (u, v, w) solution of § 34 comes 

 essentially to nothing, asymptotically as time advances, as we 

 see by (33), (34), and (38). Hence the (u, v, W) of § 37, 

 which rise gradually from zero at t = 0, comes asymptotically 

 to zero again as t increases to co . We conclude that the 

 steady motion is stable. 



[To be continued.] 



XXII. On Evaporation and Dissociation. — Part VI. (continued) . 

 On the Continuous Change from the Gaseous to the Liquid 

 State at all Temperatures. By William Ramsay, Ph.D., 

 and Sydney Young, D.Sc* 



[Plates IK.- V.] 



THE following pages give a further proof of the correctness 

 of the relation p = bt—a, where v = constant, applicable 

 both to gases and liquids. The data for methyl alcohol apply 

 solely to the gaseous state, for the very high pressures which 

 its vapour exerts precluded measurements at temperatures 

 above its critical point. With ethyl alcohol the determinations 

 of the compressibility of the liquid are more complete than 

 with ether ; the experimental observations in the neighbour- 

 hood of the critical volume are, however, not very numerous, 

 for the highest temperature for which an isothermal was con- 

 structed is 246°, the critical temperature being 243°'l. The 

 values of a and b at volumes near the critical are con- 

 sequently somewhat uncertain. The data for the gaseous 

 condition are, however, pretty full. We have also a consider- 

 able number of data for acetic acid (Trans. Chem. Soc. 1886, 

 p. 790). Here the temperature at which the highest iso- 

 thermal was measured was the highest conveniently attainable 

 by our method, viz. 280°. But as the critical temperature 

 * Communicated by the Physical Society : read April 23, 1887. 



