988 



Diffusion of 2 per cent, solutions for seven days : — 



Grs. Ratio. 



Chloride of sodium at 60° 12-14 100 



Bromide of sodium at 59°*8 .... 11*93 98*27 



Iodide of sodium at 59°*8 12*18 100*33 



Mean 12*08 



In both groups there is a near approach to equality of diflfusion. 

 The times for the salts of the two bases being in the empirical pro- 

 portion of the square roots of 2 and 3> the mean diffusates also ap- 

 proach pretty closely. 



Bicarhonates of Potash, Ammoina and Soda. — Time of diflfusion 

 8*083 days, or double that of hydrate of potash. The water of the 

 jars was partially charged with carbonic acid gas, to prevent the 

 decomposition of the bicarbonates in the act of diffusion. 



Diffusion of bicarbonate of potash in 8*08 days at 68°*2; two 

 cells : — 



Grs. Ratio. 



From 1 per cent, solution 7*23 1*029 



From 2 per cent, solution 14*05 2 



From 4 per cent, solution 26*72 3*806 



From 8 per cent, solution 52*01 7*408 



Diffusion of bicarbonate of ammonia in 8*08 days at 68°*2 ; two 

 cells : — 



Grs. Ratio. 



From 1 per cent, solution 6*91 1*013 



From 2 per cent, solution 13*65 2 



From 4 per cent, solution 27*00 3*959 



From 8 per cent, solution 50*10 7*346 



The amount and progression of the diffusion of this salt corre- 

 spond well, for all the proportions diffused, with the preceding iso- 

 morphous bicarbonate of potash. 



Diffusion of bicarbonate of soda in 9*87 days at 68°*1 ; two cells :— 



Grs. Ratio. 



From 1 per cent, solution 7*31 1*059 



From 2 per cent, solution 13*81 2 



From 4 per cent, solution 26*70 3*869 



From 8 per cent, solution 52*38 7*590 



A remarkable approach to equality in the diffusion of the bicar- 

 bonates of potash and soda, in the times chosen, is observed equally 

 in all the proportions of salt from 1 to 8 per cent. 



The times chosen for the bicarbonates of potash and ammonia is 

 to that of the bicarbonate of soda, as the square root of 2 to the 

 square root of 3, and the remarkable agreement observed in the dif- 

 fusion of these salts gives support therefore to that relation. In 

 alluding to this relation, it is, however, added that the carbonates of 

 l^otash and soda deviate from it in a sensible degree, and the hy- 

 drates of potash and soda very considerably ; so that if the relation 

 has a real foundation, it must be masked in the salts last named by 



