duly ic ipbictea haaSe 
18 Analysis of Sea Water. 
ammoniacal precipitant for every portion of bromide of sodium . 
or potassium, an equivalent of bromide of silver and chloride of — 
sodium or potassium will be formed, and the corresponding quan- | 
tity of ammonia, which kept the chloride of silver in solution, 
will be free and act upon the bromide of silver; but by observ- 
ing the before-mentioned precaution, every error of that kind 
will be avoided. Should a fluid contain iodides and bromides 
without chlorides, and not in too small a proportion, a very good 
method of ascertaining their respective quantities is to precipl- 
tate them at once with nitrate of silver, and to heat the dry pre- 
cipitate in an atmosphere of bromine. I have found, when jodie 
of silver is melted in an atmosphere of bromine, it is entirely — 
changed into a bromide; and from the difference of the weight - E 
between the mixture of ledide and bromide of silver, and that of — 
the whole bromide of silver, the respective quantities of iodine — 
k, and bromine may be ascertained. Thus the quantity of iodine _ 
(or bromine) stands in proportion to the difference of the weight, _ 
as the atomic weight of iodine (or bromine) is to the difference 
of their atomic weights. Hence it would only be required for 
. the quantity of iodine to multiply the given difference of the — 
_ weight by 2.627, and for that of bromine to multiply it by 1.627. 
Professor H. Rose, of Berlin, applies a similar method for the sep- — 
aration of iodine from chlorine.—(Poggendorff’s Ann. 1834, No. — 
37, pp. 583, 584.) ot 
I may appear to have dwelt long upon this subject, but the ime 4 
portance into which brine-springs have arisen on account of their + 
powerful components, iodine and bromine, has induced me to ex-_ A 4 
amine the matter closely, as i it may be of consequence to the med- 
ical profi ession se know the =e quantity of these valuable sue : 
stances, ee, ; 3 
I have bitty to add, that the quantity of chlorine in — : 
was ascertained by means of nitrate of silver, deducting from it 
that proportion of bromine which. had been found according t0 — 
the foregoing method, The quantity of sulphuric acid was — 
_ found by chloride of barium, the water having previously bee? t 
: with a little nitric acid. Another portion of the water ies 4 
ia es Me se 
4 OF Eye 
6 of the weight between this and the formet 
amount of carbonate of barytes, from hie 
of carbonic acid gas was com 
atl Ex 
