ON THE DIFFUSION OF LIQUIDS. 
173 
process of distillation. Thus it was shown that chlorides 
diffuse out from sulphates and carbonates, and salts of 
potash from salts of soda; and that from sea-water the salts 
of soda diffuse out into pure water faster than the salts of 
magnesia. The latter circumstance was applied to explain 
the discordant results which have been obtained by different 
chemists in the analysis of the water of the Dead Sea, taken 
near the surface ; the different salts diffusing up, with un- 
equal velocity, into the sheet of fresh water, with which 
the lake is periodically covered during the wet season. 
It was further shown that chemical decompositions may 
be produced by liquid diffusion. The constituents of a 
double salt of so much stability as common alum being 
separated ; and the sulphate of potash diffusing in the largest 
proportion. In fact, the diffusive force is one of great en- 
ergy, and quite as capable of breaking up compounds as 
the unequal votalility of their constituents. Many empiri- 
cal operations in the chemical arts, it was said, have their 
foundation in such decompositions. 
Again, one salt, such as nitrate of potash, will diffuse into 
a solution of another salt, such as nitrate of ammonia, as 
rapidly as into pure water ; the salts appearing mutually dif- 
fusible, as gases are known to be. 
Lastly, the diffusibilities of the salts into water, like those 
of the gases into air, appear to be connected by simple nu- 
merical relations. These relations are best observed when 
dilute solutions of the salts are diffused from the solution 
cell, such as 4, 2, or even 1 per cent, of salt. The quanti- 
ties diffused in the same period of seven days from 4 per 
cent, solutions of the three salts, carbonate of potash, sul- 
phate of potash, and sulphate of ammonia, were 10.25 
grains, 10.57 and 10.51 grains respectively ; and a similar 
approach to equality was observed in the 2, 4, and 6 per 
cent.solutions of the same salts. It also held at different tem- 
peratures. The acetate of potash appeared to coincide in dif- 
fusibility with the same group, and so did the ferrocyanideof 
15* 
