122 



Dr. M. Wildermann on an Experimental 



From these experimental data are deduced the following 

 Tables, in which are given : — 



a, the number of molecules of the substance dissolved, p. litre, 

 a, the lowering of the freezing-point which is observed. 

 b y the number of degrees of over-cooling read on the smaller 

 thermometer. 



c, the amount of the solvent which separated as ice, expressed 



in percentages. 



d, the factor by which the number of molecules given under 



a must be multiplied in order to obtain 

 a corrected ; i. e. the concentration of the solution after the 

 separation of the ice. (It is better to correct the 

 density than the lowering of the freezing-point, on 

 account of dissociation.) 



; — , gives the molecular lowering of the freezine- 



« corrected ° ° ° 



point, which, according to Van't HofF, is represented 



hy 0-02T 2 



t = - ^L = 1-878 (if iv = 79'6), 



IV 



or 



= 1-87 (ifw = 80). 

 Table II. 



Cane-sugar. 



a mol. norm. 



ao 



0006535 



(2.) 



0019344 



(3.) 



003164 



(4.) 



0-04344 



(5.) 



005477 



(6.) 



006565 



(7.) 



007609 



(8.) 



0-08612 



a. 



[0-0100(1)] 

 0016(7) 



[ 0-0344(5)] 

 0-0360(1) 



[0-0579(80)] 

 00595(6) 



[0-0792(1)] 

 0-0808(9) 



[0-1010(1)] 

 0-1026(7) 



[0-1224] 

 0-1240(1) 



[0-1430(1)] 



0-14407-8) 



[0-1624(5)] 

 01640(1) 



b. 



c. 



d. 



a corr. 



0006602 



019548 



003192 



004386 



005527 



0-06619 



0-07678 



0-08679 



6-888 

 0-855 

 0-731 

 0-789 

 0-755 

 0-673 

 0-751 

 0643 



per cent. 

 106 



103 



0-88 



0-95 



0-91 



0-81 



0-90 



0-77 



100 

 98 94 



100 

 98-97 



100 

 9912 



100 

 9905 



100 

 9909 



100 

 9919 



100 

 99-1 



100 

 99-25 



0= 



a corr. 



XlOO 



[151-5] 

 175-7 {177-2) 



[176 (176-5)1 

 184-5 (184-7) 



[181-4 (181-7)]- 

 186-4 (186-7) 



[180-6 (180-3)] 

 184-3 (184-5) 



[182-7 fl-<2-9)] 



185-6 (1858) 



[184-9] 

 187-3 (187S) 



[186-2(186-4)] 

 188-3 (1885) 



[187-1 (187-3)] 

 189-0 (189-1) 



