236 RELATION OF PHYSICAL PROPERTIES OF AQUEOUS SOLUTIONS 
by Grotrian*, who found that, in general, with increasing 
concentration both of these temperature-coefficients undergo 
changes in the same sense. Grossmann? claimed to have proved 
these coefficients to be equal; but afterwards withdrew the 
claim as based on an error{. Kohlrausch and Hallwachs also 
have noticed for very dilute solutions a close similarity between 
the curves representing the density and the conductivity 
respectively of the same salt as functions of the concentration. 
The following tables show that this family likeness extends, 
to a greater or less extent, to all the coefficients for at any 
rate a considerable number of the properties of solutions. The 
tables include some of Grotrian’s coefficients with others calcu- 
lated from the observations of Kohlrausch, Bender, Brickner, 
Rother, Rontgen and Schneiders, Fink ||, and Timberg {. The 
coefficients are in almost all cases mean values, the ranges of 
temperature, &c., to which they apply, though che smallest for 
which data are available, being not in all cases the same. As I 
wish to show only a general similarity, it is not necessary to 
specify the ranges. The temperatures, &., of the lower limits 
of the ranges are also not in general exactly thesame. The data 
of the tables are thus not exactly comparable; but they are 
sufficiently so for my purpose. The heading 7 stands for 
gramme-equivalents per litre. 
* Wied. Ann. viii. (1879) p. 552. 
+ Ibid. xviii. (1883) p. 119. 
t See Kohlrausch, Wied. Ann. xxvi. (1885) p. 224. 
§ Wied. Ann. xxix. (1886) p. 194. 
|| Ibid. xxvi. (1885) p, 505. 
q Ibid. xxx. (1887) p. 545. 
