1903-4.] Physico-Chemical Investigations in Amide Group. 59 
to express my thanks. With these solutions I have calculated 
values of the viscosity from the formula 
p , a 2 x 2 ah- 2, 
' t 2 ! 3 ! 
} 
where R is the viscosity of the KC1 or HC1 and the other letters are 
as before. 
Potassium Chloride and Urea (25° C.). 
Concentration. 
Viscosity 
A 
Observed. 
Calculated. 
| norm. KC1 
•995 
,, +| mol. urea, . 
1007 
1 006 
rH 
o 
o 
33 +2 >> 
1*017 
1*017 
3 5 + *7 ,, 
1*030 
1*026 
- *004 
3, +1 • 
1*043 
1*040 
- *003 
3, +1*4 „ 
1*066 
1*058 
- *008 
33 +1'6 ,, 
1*075 
1*068 
- *007 
‘ a ’ is here taken equal to -044, as also in the next series. 
Hydrochloric Acid and Urea (25° C.). 
Concentration. 
Viscosity 
A 
Observed. 
Calculated. 
i norm. HC1 
1*033 
,, +| mol. urea 
1*045 
1*045 
3 3 + 2 3 3 
1*054 
1*056 
+ '*002 
,, + '7 
1*063 
1*065 
+ *002 
3 3 +1 3 3 
1*081 
1 080 
- *001 
3 3 + 1 *4 3 3 
1*102 1 
1*099 
- *003 
3 3 + 1 0 , , . . 
1*114 > 
1*109 
- *005 
The observed and calculated values for the case of KC1 and 
CO(NH 2 ) 2 agree very well up to 1 mol. urea. For the case HC1 
and CO(NTI 2 ) 2 the agreement is also fairly good. 
The viscosity of KC1 and CO(NH 2 ) 2 is represented in fig. 5 : 
it appears as almost an exact reverse * of the conductivity curve 
(fig- 3). 
* Compare also Phil. Mag., 6, iii. 487 (1902). 
