1904-5.] Note on Boiling Points of Aqueous Solutions. 955 
constant expressed per gramme particle (molecule or ion) in one 
gramme of solvent — 
m = molecular weight of salt added. 
W = weight of solvent used in grammes. 
E = elevation of boiling point. 
w = weight of salt added in grammes. 
a = ionization coefficient. 
n = number of free ions into which a molecule of salt dissociates. 
From this formula values of C were obtained, at one time high, 
at another low, when compared with theory. Thus, for potassium 
chloride the values 858, 704, 684, 643, 614, 596, 572 were 
obtained from one series; a second series gave 460, 467, 514, 
518, 523. For potassium nitrate the values were 637, 617, 603, 
573, 571, 549, 547, 540, and a second series gave 874, 702, 696, 
686, 643, 608, 609, 593 ; for a third series the values were 605, 
556, 550. For sodium nitrate 518, 516, 520, 529, 534, 530, 535. 
For sodium chloride 617, 621, 592, 587, 579. 
Such values as these being obtained, it was desirable to see 
what values would be given by calculations from the boiling point 
data of other experimenters. Elevations of boiling point as given by 
Biltz * gave for potassium nitrate as values 638, 589, 596, 628, 
and for sodium chloride 585, 598, 611, 609. Those given by Walker 
and Lumsden f gave for potassium nitrate 648, 618, for sodium 
chloride 598, 593, and for potassium bromide 620, 614, 645, 665. 
Smitz’s % elevations gave for sodium chloride 463, for potassium 
chloride 497, for potassium nitrate 522, and for sodium nitrate 594. 
From observations I made, it would seem that these high values 
are the result of a difficulty in the determination of the exact 
boiling point of water. Thus, for the solvent, a steady boiling 
temperature could be raised or lowered by increasing or decreasing 
the strength of the source of heat, within the range of several 
hundredths of a degree. A solution, on the other hand, took up 
a definite boiling temperature, which was independent of small 
changes in the strength of the source of heat so long as ebullition 
was maintained. 
* Practical Methods for determining Molecular Weights, translated by Jones 
and King, 189. 1899. 
t Journal of the Chemical Society, 73, 502. 1898. 
t Zeitschrift fur physicalische Chemic, 39, 420. 1902. 
