200 TT. S. Hunt on the Chemistry of Natural Waters. 
from the sea-waters, and its fixation in the earth’s The 
observations of numerous chemists unite to show the frequent 
occurence of small portions of iodi some unkn 
sea, either directly or through the intervention of organic bodies 
(as in the case of potash, which is separated and fixed by means 
of alge, § 5). Experiments after the manner of those of Way 
and Voelcker may throw light upon this interesting question, 
We are aware that insoluble combinations of soluble chlorids 
with silicates of alumina are found under certain conditions, as 
appears in the generation of sodalite, eudialyte, and the chlorif- 
erous micas, and it is not improbable that the soluble iodids may 
give rise to similar compounds, By such a process might be 
explained the rarity of this element in modern seas, while the 
occasional re-solution of the iodine from these insoluble com- 
Pr 
The elimination of sulphate in the form of gypsum from evap- 
orating waters conta 
already been discussed in § 37; but the bitterns resulting from 
such a process still retain small portions of sulphates, while it 18 
to be remarked that the saline waters under consideration Ccon- 
tain no traces of s1 rti 
rets. These in their turn may be converted into carbon- 
__ ates, the sulphur being separated either as sulphuretted hydro- 
gen (giving rise by o: ydation to free sulphur), or as insoluble 
