484 
PROFESSOR GRAHAM ON THE DIFFUSION OF LIQUIDS. 
Diffusion of Hydrate of Potash in 4*04 days at 63°'4 ; two cells. 
From 1 per cent, solution . 
Grs. 
. . 6*56 
Ratio. 
1*022 
From 2 per cent, solution . 
. . 12*84 
2 
From 4 per cent, solution . 
. . 25*04 
3*900 
From 8 per cent, solution . 
. . 52*24 
8*137 
Hydrate of Soda . — Time of diffusion 4*9497 days; the times chosen as hitherto 
for the corresponding potash and soda salts being always, when squared, in the pro- 
portion of 2 to 3. The usual number of eight cells of the I 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 hydrate of soda 
diffused for two cells determined by alkalimetric experiments. 
1. T043 percent, of hydrate of soda, density 1 0 1256, diffused at 63°'3, gave 6*06 grs. 
for two cells ; calculated for 1 per cent., 5'81 grs. of hydrate of soda in two cells. 
2. 2'()87 per cent, of hydrate of soda, density 1*0242, diffused at 63°*3, gave 1T58 
grs. for two cells ; calculated for 2 per cent., 1 1*09 grs. of hydrate of soda in two cells. 
3. 4*177 per cent, of hydrate of soda, density 1*04666, diffused at 63°*3, gave 
10*90 grs. for one cell; calculated for 4 per cent., 10*43 grs. of hydrate of soda in 
one cell. 
4. 8*35 per cent, of hydrate of soda, density 1*08846, diffused at 63°*3, gave 21*10 
grs. for one cell ; calculated for 8 per cent., 20*22 grs. of hydrate of soda in one cell. 
Diffusion of Hydrate of Soda in 4*95 days at 63°*3 ; two cells. 
Grs. 
Ratio. 
From 1 per cent, solution . 
. . 5*81 
1*048 
From 2 per cent, solution . 
. . 11*09 
2 
From 4 per cent, solution . 
. . 20*86 
3*765 
From 8 per cent, solution . 
. . 40*44 
7*30 
The nearest approach to equality of diffusion in the hydrates of potash and soda, 
is exhibited by the 1 per cent, solutions, which are as 6*56 to 5*81, or as 100 to 88*57, 
being a difference of so much as 1 1*43 per cent. 
Comparative Diffusion of Hydrate of Potash in 4*041 days at 63°*4, and of 
Hydrate of Soda in 4*95 days at 63°*3. 
From solutions of 
1 per cent. 
2 per cent. 
4 per cent. 
8 per cent. 
Hydrate of poteish 
100 
88-57 
100 
86-37 
100 
83-30 
100 
77*41 
Hydrate of soda 
The marked departure from the usual ratio of diffusion, here exhibited, must not 
be overlooked in considering the relation between potash and soda salts. 
