954 Proceedings of Royal Society of Edinburgh. [sess. 
tivity at 99° '4 C. for solutions containing one, one-half, one-fourth, 
one-eighth, etc. and one-thousandth gramme equivalents per litre. 
The ionization at any of these concentrations was obtained by 
dividing the conductivity value, as given by Kranhals, by the value 
at one-thousandtli gramme equivalents. The concentration ioniza- 
tion curve was drawn on sectional paper for the range of a series 
of experiments. From the amount of salt added to the solvent the 
percentage composition was obtained, from which, by the aid of 
tables,* the concentration in equivalent gramme molecules per litre 
was obtained, and for this the ionization by the use of the 
ionization concentration curve already referred to. Ivranhals 
claims to work with an error limit of from two to three per cent. 
Having repeated many of his experiments, I found this claim well 
justified. Schaller, and Lyle and Hosking have also done some 
conductivity work at 99° or 99° ’4. Kranhals’ values were chosen 
because they were best suited to series of experiments within the 
range of this note. Lyle and Hosking f deal chiefly with sodium 
chloride solutions. Schaller J worked principally at 256, 512, and 
1024 litres per gramme equivalent. Values up to 80° have been 
given by Trotsch,§ and Campetti and Nazari,|| which would be too 
low a temperature for my purpose. Those who have given con- 
ductivity values up to 99° or 99° - 4 have only given them to about 
one-thousandth gramme equivalents per litre, which dilution 
could scarcely be supposed to give the molecular conductivity at 
infinite dilution for every salt. 
I therefore intend to make determinations of conductivity at 
greater dilution. 
When calculating the results obtained by experiment, at 
first , total elevations above the boiling point of the solvent 
were used. The calculations were made from the formula 
c _ m.W.E 
(1 +n~ la )w 
where C is the value of the so-called boiling point elevation 
* B. A. Report on the Present State of our Knowledge of Electrolysis and 
Electro- Chemistry , 1 893. 
t Phil. Mag. (6), 3, 487. 1902. 
+ Zeit. f. phys. Chem ., 25, 497. 
§ Wied. Annalen, 41, 259. 1890. 
|| Acad. Science Torino , 40, Nos. 2 and 3, pp. 155, 163. 1904-5. 
