289 
_ with the exception of the alkaline ones, and the bromine 
being supposed united with magnesium, and a deduction 
made from the calcium for the small amount of sulphate of 
lime present, it was easy, by giving to the manganese and 
earthy metals their proper proportions of chlorine, to infer 
the quantity of this principle united with the potassium and 
sodium. Let this quantity, which was found greater than 
what resulted from the direct determination of the chlorides 
of these metals, be called w, and let m be to nin the ratio of 
the chloride of potassium to the chloride of sodium, as 
already determined. Let x, also, be the true weight of the 
chloride of potassium, y the true weight of the chloride of 
sodium, a the ratio of the atomic weight of chloride of potas- 
sium to chlorine, and 4 that of chloride of sodium to chlorine. 
We will thus obviously have the two following equations : 
an+by=w; and, nx =my; 
from which we readily deduce 
mw nw 
a Fs ma + nb? apd Ss ma + nb° 
From a fresh portion of the water the sulphuric acid was 
got by nitrate of barytes, and the sulphate of barytes having 
been separated, the chlorine and bromine were thrown down 
in union with silver.* To infer, however, from this mixed 
precipitate, the chlorine, it was necessary to estimate the 
bromiue present by a distinct process. 
With this view, a strong aqueous solution of chlorine 
was mixed with a known weight of the water under analysis, 
and the bromine liberated was removed by repeated wash- 
ings with ether. From the etherial solution, the bromine mixed 
with some chlorine was separated by barytic water, and the 
ether being distilled off, the residue was evaporated to dry- 
ness, and ignited, so as to reduce any bromate and chlorate 
* The excess of silver having been separated from the solution, by chloride of 
sodiam, the manganese was thrown down by the addition of hydrosulphate of ammo-~ 
nia. This metal was also estimated by the process recommended by Stromeyer. 
