512 Dr. W. W. J. Nicol on the Vapour-pressures 



100 water. This is connected with the value - — — x 10,000, 



which I have used above in the following way 



w=~j where a=mol. wt. of salt, 

 a 



18 



np 



ip-p')x looo/i 



pm 



l)xl00= 

 18 



P-P 

 np 



x 10,000. 



Now as Tammann's temperatures are variable, it is necessary 

 to use this value in comparing his results; and, again, as his 

 figures vary within rather wide limits, better results are 



T—T' 

 obtained by taking the mean value of — pp— x 1000 for tem- 

 peratures lying on either side of the desired temperature. 



Table IX. compares results for t°=7i)° and 90°, and for 

 various strengths of NaCl, and for various solutions of the 



Table IX. 





Tammann. 



Nicol. 



Salt. 



t°. 



n. 





t°. 



n. 





NaCl 



» 



>» 



712 



71-2 

 712 



4-55 



6-75 



10-97 



190 

 208 

 219 



70° 



» 



90° 

 » 



5 



6 



10 



198 

 207 

 221 



NaCl 



>} 



» 



90-8 

 90-8 

 90-8 



4-55 



675 



1097 



190 

 201 

 216 



5 



6 



10 



202 

 203 

 216 



KOI 



71-6 

 >> 



3-33 

 6-45 



179 

 183 



70° 



4 

 6 



181+2 

 185 ±2 



NaN0 3 ... 



„ 



,, ... 



720 



9) 



322 



5-58 



11-12 



19-30 



170 

 164 

 160 

 136 



70° 

 >» 



4 



6 



10 



20 



176 

 167 

 161 

 144 



KN0 3 



3> 



>> 



>> 



>> 



69-8 



72-7 



69-8 



»> 



2-26 



315 



7-31 



15-31 



20-59 



151 



111 



95 



96 



96 



70° 



3 



3 



5 



15 



20 



144 

 146 

 138 

 107 

 99 



