PROFESSOR GRAHAM ON OSMOTIC FORCE. 
223 
la the first experiment with a double membrane the osmose of the salt in question 
was 38 ms., but the osmose fell in the second and third repetitions to 12 and 17 ms. 
The 4 per cent, solution of the same salt gave no more than 23 and 7 ms. 
Mercury . — The osmose of the salts of both oxides of this metal is always positive 
and generally considerable. The osmose appeared to be of least amount in the 
chloride (corrosive sublimate), to increase in the protonitrate, and to assume its 
greatest magnitude in the pernitrate. The first salt has a stability in solution which 
the latter two salts do not enjoy. 
Extraordinary osmose is here, therefore, associated with facility of decomposition, 
as in so many other instances. 
The influence of the presence of acids and of chloride of sodium upon the osmose 
of chloride of mercury was tried in the search for facts which might throw light on 
the osmotic process. 
An acid in small proportion appears to favour, rather than otherwise, the osmose 
of chloride of mercury. Chloride of sodium, on the other hand, exerts its usual 
repressing influence upon the process. 
Table XXVIII. — Solutions of Mercury in Osmometer C of double membrane for five 
hours. 
Proportion of salt in solution. 
Rise in 
millimeter 
degrees. 
Previous 
maceration. 
Hydrostatic 
resistance. 
Temperature, 
Fahr. 
116 
days. 
min. 
1 per cent, of chloride of mercury 
4 
4 
60 
Same 
121 
3 
4 
61 
0 - l per cent, of chloride of mercury 
62 
1 
4 
63 
Same 
49 
1 
5 
66 
1 per cent, of chloride of mercury + 0 - l per j 
163 
1 
5 
62 
cent, of hydrochloric acid / 
Same + same 
132 
1 
4 
6l 
Same + 0*1 per cent, of nitric acid 
152 
3 
5 
60 
Same + same 
122 
1 
2 
59 
Same + 0 - 5 per cent, of chloride of sodium... 
72 
1 
2 
61 
Same + same 
60 
1 
1 
62 
Adopting the second experiments as the most trustworthy, we have for 1 per cent, 
of chloride of mercury an osmose of 121 ms., and for the same, associated with half 
its weight of chloride of sodium, 60 ms. 
The osmose of chloride of mercury in albumen was very trifling, being only 5 and 
9 ms. ; chloride of mercury diffused in sensible quantity, however, through both the 
albumen and membrane. 
Protonitrate of mercury gave, in double membrane, an osmose of 232, 346 and 
350 ms. ; in albumen, much less, namely 47, 63 and 61 ms. 
Pernitrate of mercury gave, in double membrane, 425 and 476 ms. for the one per 
cent, solution, and 296 ms. for the one-tenth per cent, solution, results which 
indicate osmotic power of the highest intensity. 
