238 RELATION OF PHYSICAL PROPERTIES OF AQUEOUS SOLUTIONS 
A glance at these tables shows that if regard be had to sign, 
Grotrian’s conclusion as to the temperature-coefticients for con- 
ductivity and fluidity applies to all the coefficients for all the 
properties tested. A given change in the concentration pro- 
duces a change in the coefficients in the same sense. Too much 
importance, however, must not be attached to this; for it is 
obvious that if we should tabulate, say, the coefficients for con- 
ductivity, surface tension, viscosity (instead of {luidity) and 
specific volume (instead of density), it would be found that the 
changes produced in the first two are in the opposite sense to 
those produced in the last two. It is interesting, however, to 
note that the expectation suggested by the above formule is 
distinctly realized. 
At very great dilution of electrolytes, the temperature-coeffi- 
cient becomes, approximately, 
dob, Oe, 
Pale ee 
the pressure-coeflicient having e same form. The concentra- 
tion-coefticient becomes 
a Spt: ete: yore (10) 
If we compare (9) and (10) with (7) and (8), it becomes 
obvious that the variation with concentration of the tempera- 
ture and pressure coefficients will probably be more closely 
related at low than at high concentrations, but that the oppo- 
site will be true of the concentration coefficients. Accordingly, 
having plotted Grotian’s coefficients and those of the above tables 
as functions of the concentration, I find that the temperature 
coefficient curves, tor any one substance in solution, are in 
general more closely similar at low than at high concentrations ; 
but that this is not the case for the concentration coefficient 
curves. In the case of the pressure coefficients the data are 
insufficient. . 
A corresponding similarity holds for the absorption spectra 
=| [(e\ = 1) eee (9) 
of solutions though it cannot be expressed in coefficients. In a 
former paper * I have shewn that for all solutions for which 
* Trans. Roy. Soc. Can., ix (1891), sec. 3, p. 27. 
