1903-4.] Pkysico- Chemical Investigations in Amide Group. 57 
investigated this by measuring the electrical conductivity of 
sodium hydrate solution with varying additions of urea.* 
Sodium Hydrate and. Urea ; 25° C. 
\ norm. 
? 5 
5 5 
Concentration. 
NaOH, . 
, M 
,, +— urea, 
4 
M 
” + 2 ” 
„ +M „ 
,, + 2M ,, 
Molec. Conductivity. 
194-2 
191*8 
188*7 
183-0 
172-0 
By adding \ mol. urea to hydrochloric acid, potassium chloride 
and sodium hydroxide, we obtain depressions of the conductivity 
by 23*6%, 1'6%, and 2-8% respectively. As, among anions, - OH' 
wanders faster than any other ion, we would have expected a much 
* Winkelblech (Zeit. fur physikal. Chemie , 36, 576 { 1 901 } ) has experi- 
mented with dilute solutions to y^-g- molec. ; at these dilutions signs of 
salt formation could hardly be expected. 
