﻿and some Applications to Pliysical Measurements. 499 



This gives 



K r = 67'OxlO- 6 c.g.s., 

 and finally 



K m = 62'4 x 10- 6 c.g.s. at 16° C. 



The results of the two tests thus give as mean values 



K„= 66'5 x 10" 6 c.g.s., 



K TO = 61-9 x 10" c c.g.s. at 16° C. 



For the complete salt Finke * finds K„ — 68 x 10~ 6 c.g.s. 

 The mean values for K m in the Tabellen is 66 x 10~ 6 c.g.s., 

 while Theodorides t gives for K TO the value 64*5 x 10" 6 c.g.s. 

 at 16° C. 



VII. Cobalt Chloride.— -The salt was examined in the 

 form of a solution in air-free water. It occupied a volume 

 1*620 c.c. and had a length in the glass tube 8 cm. The 

 density was determined to be 1*186 gm. per c.c, and an 

 electrolytic estimation yielded 0*2078 gm. CoCl 2 per c.c. 

 The observations are shown in Table X. 



Table X. 



Wave-length 



of Set 2 



in metres. 



Frequency 

 of Set 2. 



N. 



Frequency 

 of Set 1. 



»=N/2. 



Change in 



number of 



beats per sec. 



p — '2dn. 



p/N. 



Tempera- 

 ture 

 degrees C. 





XlO 5 



XlO 5 





XlO -6 





340 



8-82 



441 



3-48 



394 



20 



385 



7-80 



3-90 



3-09 



396 



20 



414 



7-25 



3-61 



2-85 



394 



20 



Mean p/N=3'95xl0- 6 at 20° O. 

 This gives 



K c = 19-30 XlO" 6 c.g.s., 



from which we find for the mass susceptibility of the solution 



K mi = 16*28 XlO" 6 c.g.s., 

 and finally for the mass susceptibility of the water-free salt 

 K m = 81-3xl0-« c.g.s. at 20° C. 



* Finke, loc. cit. 



t Th6odorid.es, loc. cit. 



2 K 2 



