ES Sy Analysis of Sea Water. 
silver to subside. It is well when bromides are present to keep 
the vessel closed during the process, otherwise it is of no impor- 
tance. The iodide of silver collected upon a small filter was 
first washed with a little diluted ammonia, and afterwards with 
a few drops of diluted hydrochloric acid to dissolve any earthy 
substance which the precipitate might contain, and ultimately 
with pure water. 
The filter with the precipitate was dried and ignited. This © 
experiment, repeatedly performed, yielded the most satisfactory . 
results. It requires time, but this is more than balanced by its 
accuracy. Thus, for instance, I obtained by the analysis of the 
Congress spring of Saratoga, from 100,000 grs. of the water, 
012164 gr. of iodide of silver, representing in 1000 grs. of the 
mineral water, 0:00067 gr. of iodine. 
ammoniacal fluid, separated from the iodide of silver, was 
cipitate was obtained, consisting of bromide of silver, which was 
added to that subsequently obtained. This precipitate was form- 
ed by the solution of the chloride of silver, more of which was 
added than was required for the separation of the iodine. That 
carefully evaporated to expel the ammonia, whereby a small pre- 
: 
this minute precipitate consisted of bromide of silver, was — 
proved by heating it in a test tube with concentrated sulphuric — 
acid, whereby it became of a delicate yellow color; whereas 
chloride of silver would have remained white, and iodide of sil- 
ver would have obtained a brown color by parting with its 
iodine. 
A small portion of the fluid may now be examined for bro- — 
mine, and, when present, the following process may be adopted, 
which is the same I employed for the separation of bromine in 
sea-water and brine-springs, where the quantity of chlorides is — 
comparatively very large. The concentrated solution freed from 
the iodine was introduced into a glass ball, having at its lower 
end a glass tube, and at its upper an aperture closed by a glass 
stopper. A concentrated aqueous solution of chlorine was added 
as long as any sensible yellowness was caused by its addition. 
The fluid was then agitated with pure ether ; and after this had 
collected on the surface, carrying with it the bromine and ehlo- 
bee the water was allowed to flow off through the tube below, — 
efu Eesinulation. the ether could then be freed from 
