Diseases of the latter kind are especially interesting, as in them we see that parts of the nervous structure, separated in space, may nevertheless be associated in function; for instance, wasting of a group of muscles associated in function may depend on a set of central degenerations concurring in parts whose connexion, in spite of dissociation in space, we thus perceive.
The operation is essentially a dissociation of alumina into aluminium, which collects at the cathode, and into oxygen, which combines with the anodes to form carbon monoxide, the latter escaping and being burnt to carbon dioxide outside.
Electrolytic or ionic dissociation is the separation of a substance in solution into ions (see Electrolysis; Solution).
Let us consider the case of the neutralization of a base by an acid in the light of the dissociation theory.
There must be considerable dissociation of molecules, and as a first approximation it may be taken that of io molecules of most of the components about 9 (or in the case of magnesium sulphate 5) have been separated into their ions, and that it is only during slow concentration as in a natural saline that the ions combine to produce the various salts in the proportions set out in the above table.
The ordinary laws of chemical equilibrium have been applied to the case of the dissociation of a substance into its ions.
For strong solutions the discrepancies from Raoult's law often become very large, even if dissociation is allowed for.
In the case of weaker acids, the dissociation of which is less complete, divergences from this constant value will occur, for some of the molecules have to be separated into their ions.
This takes place when in the manufacture of the carbide the material is kept too long in contact with the arc, since this overheating causes the dissociation of some of the calcium carbide and the solution of metallic calcium in the remainder.
In simple substances like potassium chloride it seems evident that one kind of dissociation only is possible.