PROFESSOR GRAHAM ON THE DIFFUSION OF LIQUIDS. 
813 
16'21 grs. for one cell. Calculated for 4 per cent., 16’50 grs. of sulphurous acid in 
one cell at 68°’ 1. 
4. 7'86 per cent, of sulphurous acid, density 1*0384, dilfused at 68°*1, gave 32*60 
grs. for one cell. Calculated for 8 per cent., 33*19 grs. of sulphurous acid in one cell 
at68°*l. 
Diffusion of Sulphurous Acid in ten days at 68°*1 ; two cells. 
Grs. 
Ratio. 
From 1 per cent, solution . . 
8*09 
0*954 
From 2 per cent, solution . . 
. 16*96 
2 
From 4 per cent, solution . . 
. 33*00 
3*891 
From 8 per cent, solution . . 
. 66*38 
7-827 
This substance appears to be less diffusive than sulphuric acid at the same tempe- 
rature; the diffusion of sulphurous acid at 68°*1 considerably resembles that of sul- 
phuric acid at 49°*7 (p. 811). 
9. Ammonia. 
The time of diffusion chosen was 4*041 days, or that of hydrate of potash with 
chloride of sodium at seven days. The usual number of eight cells of the 1 and 2 per 
cent, solutions were diffused, and four cells of the 4 and 8 per cent, solutions. The 
whole diffusates of each proportion were then mixed together, and the quantity of 
ammonia diffused for two cells determined by an alkali metrical experiment, which 
was always repeated twice. It was necessary for diffusion to have the ammoniacal 
solution made denser than water, which was effected by the addition of common salt. 
1. 1*005 per cent, of ammonia, density made up to T00352 with chloride of sodium, 
diffused at 63°*4, gave 4*96 grs. for two cells ; calculated for 1 per cent., 4*93 grs. 
of ammonia in two cells at 63°*4. 
2. 2*01 per cent, of ammonia, density made up to 1*00617 with chloride of sodium, 
diffused at 63°*4, gave 9*64 grs. for two cells ; calculated for 2 per cent., 9*59 grs. of 
ammonia in two cells at 63°*4. 
3. 4*02 per cent, of ammonia, density made up to 1*01141 with chloride of sodium, 
diffused at 63°*4, gave 9*91 grs. for one cell; calculated for 4 per cent., 9*86 grs. of 
ammonia, in one cell, at 63°*4. 
4. 8*04 per cent, of ammonia, density made up to 1*0215 with chloride of sodium, 
diffused at 63°*4, gave 20*71 grs. for one cell; calculated for 8 per cent., 20*61 grs. 
of ammonia in one cell at 63°*4. 
Diffusion of Ammonia in 4*04 days at 63°*4 ; two cells. 
Grs. 
Ratio. 
From 1 per cent, solution . 
. . 4*93 
1*029 
From 2 per cent, solution . 
. . 9-59 
2 
From 4 per cent, solution . 
. . 1972 
4*117 
From 8 per cent, solution . 
. . 41*22 
8*605 
