( 164 ) 
Na Cl 
Concentration Pm 
in gr. mol. per| in mm. Hg i 
1000 gr. H,O. of 0°. 
0.0591 0.149 1.79 
0.0643 0.146 1.76 
0.1077 0.143 1.72 
0.1426 0.142 lea! 
0.4527 0.141 1.70 
0.4976 0.141 1.70 
1.0808 0.1432 1.723 
1.2521 0.1439 1.730 
| H, SO, | 
0.0951 0.169 2.08 
0.1208 0.156 1.87 
0.4215 0.1603 1.93 
0.9762 0.1716 2.063 
| KNO, | 
0.0400 0.153 1.8 
0.1450 0.131 1.58 
0.5997 0.1156 1.39 
0.9288 0. 1084 1.304 
From this table follows that pm (decrease of molecular vapour- 
tension) and # attain a minimum in solutions of NaCl and of Hz SO,. 
For NaCl this minimum lies near 0,45 gr. mol., for Ho SO, it appears 
near + 0,1 gr. mol. The observations render the existence of these 
minima very probable, for they appear in a region of concentration, 
where the accuracy is still great enough to be sure of the course. 
As to the absolute value of pm and «4, we must keep in mind 
