PROFESSOR GRAHAM ON THE DIFFUSION OF LIQUIDS. 
13 
force is nothing more than the diffusive tendency, it will follow that salts which can 
be taken down by charcoal must be less diffusible than those which cannot. 
Of sul})hate of ammonia and sulphate of copper, solutions were prepared, consist- 
ing of 4 anhydrous salt to 100 water, the sulphate of ammonia being of course taken 
as NH4O . SO3. The solution of the copper salt was divided into two portions, one 
of which had caustic ammonia added to it in slight excess, so as to produce the azure 
blue solution of ammonio-sulphate of copper. 
The solutions were diffused for eighj; days, at a mean temperature of 64°'9 for the 
sulphates and nitrates, and 67°'7 foi’ the chlorides. 
Table VI. — Diffusion of solutions, 4 salt to 100 water. 
Name of salt. 
Density of solution 
at temperature of 
experiment. 
Anhydrous salt 
diffused in grains. 
Sulphate of ammonia 
1-0235 
12-13 
Sulphate of ammonia 
1-0235 
11-96 
Sulphate of cooper 
1-0369 
6-19 
Sulphate of copper 
1-0369 
6-51 
Ammonio-sulphate of copper 
1-0308 
1-45 
Ammonio-sulphate of copper 
1-0308 
1-43 
Nitrate of ammonia 
1-0136 
16-15 
Nitrate of ammonia 
1-0136 
15-44 
Nitrate of copper 
1-0323 
9-77 
Nitrate of copper 
1-0323 
9-77 
Ammonio-nitrate of copper 
1-0228 
1-77 
Ammonio-nitrate of copper 
1-0228 
1-36 
Chloride of ammonium 
1-0100 
16 -I 8 
Chloride of ammonium 
1-0100 
17*00 
Chloride of copper 
1-0328 
10-83 
Chloride of copper 
1-0328 
10-48 
Ammonio-chloride of copper 
1-0209 
4-54 
Ammonio-chloride of copper 
1-0209 
3-94 
It is to be observed, that in preparing the ammoniated salts, the solutions of the 
neutral salts of copper were slightly diluted by the water of the solution of ammonia 
added to them, so that the proportion of salt of copper which they possessed was 
sensibly reduced below 4 per cent. On the other hand, the copper salt which diffused 
out is estimated, not as ammoniated, but as neutral salt. It will be observed that the 
quantity of sulphate of copper diffused out in the experiments falls from 6*35 in the 
neutral salt to T44 gr. in the ammoniated salt; of nitrate of copper from 9*77 to 
T56, and of chloride of copper from 10*65 to 4*24. These numbers are to be taken 
only as approximations; they are sufficient however to prove a much reduced dif- 
fusibility in the ammoniated salts of copper. 
It will be remarked that the nitrate of ammonia and chloride of ammonium ap- 
proximate, 15*80 and 16*59 grs. ; as do also the nitrate and chloride of copper, 9*77 
and 10*65 grs. ; the chlorides, which were diffused at the higher temperature by 2°*8, 
exceeding the nitrates in both cases. 
