36 On the Gaseous, Liquid, and Solid States of Water. [Dec. 11, 



amendments in the way of interpolation in that column, I find that, 

 according to the experimental results as they are represented in this 



* 



Table, the value of at the freezing-point would come out to be about 

 3p 



dt 



1-05 or 1-06. "We have seen by the new calculation, based on theory, in 

 the present paper that it ought be 1'13 ; so here the feature is found 

 showing itself in about half the degree in which, according to the new 

 quantitative calculation, it ought to be met with. When we consider 

 that Begnault's reductions of his experimental results in the making out 

 of curves, formulae, and tables for representing them in the aggregate 

 were, as we have sufficient ground to suppose, carried out under the idea, 

 now proved to be erroneous, of there being, for aqueous vapour, con- 

 tinuity in variations of pressure with variations of temperature past the 

 freezing-point, just as past any other point of temperature, and when we 

 further consider that the quantities with which we are here concerned are 

 indeed very small, it is not surprising that there should have been a 

 tendency to smooth off this feature on the supposition that any depar- 

 tures of the experimental observations from the course of a continuous 

 or smooth curve were only slight irregularities due to experimental 

 errors or imperfections. 



It may now, in conclusion, be remarked that if from experiments inde- 

 pendent of those which have been made, or may be made, directly on the 

 pressure of aqueous vapour at different temperatures near, the freezing- 

 point, both above and below it, very correct determinations of the values 

 of the quantities C, M, and M' can be made, such determinations will 



lead to more correct evaluations of -^ and -jj^ for aqueous vapour in 



contact in the one case with liquid water, and in the other with ice, than 

 we at present possess. Such determinations, we may presume further, 

 would, if very trustworthily arrived at, conduce to the attainment of a 

 more correct estimate of the density of steam at the freezing-point (or at 

 the triple point) than we now possess. In fact, in connexion with the 

 subject which has been here under consideration, there are various im- 

 portant quantities so connected that improved determinations of one or 

 more of them may lead to more correct evaluations of others. 



