248 Proceedings of Royal Society of Edinburgh. [sess. 
theory of “ magnesium hypoiodite.” In nearly all cases of absorp- 
tion from solution the amount absorbed varies as a root of the 
final concentration of the solution. This simply means that a 
very slight percentage change in the concentration of the solution 
always occasions a proportional percentage change in the amount 
absorbed, no matter what the absolute values may be. It is true 
that “ solid solutions ” form a particular case of this general rule, 
but it does not therefore follow that all absorptions which come 
under the rule are solid solutions. 
The general result of this investigation is, then, that so far as 
our experiments extend, the absorption of iodine by magnesia is 
similar to other cases of absorption, though what the nature of 
such absorptions may be is at present undetermined. 
