Mr. A. B. Northcote on the Brine-springs of Cheshire. 465 
bubbles of chlorine; this element was therefore determined by 
the method recommended by Fehling*, which depends upon the 
fact, that if a solution of chloride of sodium containing a small 
amount of bromide be insufficiently precipitated by nitrate of 
silver, the precipitate nevertheless contains all the bromine pre- 
sent ; the bromine in the mixed precipitate of chloride and bro- 
mide of silver is then determined by the passage of chlorine over 
the fused mass in the usual way. The results yielded by this 
process, which were carefully and frequently repeated upon very 
different quantities of brine, agreed among themselves in the 
closest manner. The existence of iodine was proved in all the 
waters, but the quantity present was minute intheextreme. In 
one case also an indication of fluorine was obtained by the appa- 
rently etching action exerted upon a watch-glass in the applica- 
tion of the test now usually employed: these markings, however, 
on the parts uncovered by wax, although quite obvious when 
the newly-cleaned glass was breathed upon, were perfectly im- 
perceptible when the same watch-glass was taken up a day or 
two later and re-wiped for the purpose of fresh examination +. 
Since that experiment, M. Nicklés’ observations{ on the fal- 
lacies incidental to this method of testing have appeared; and 
this doubtless was a case such as he describes, in which the 
vapour of any acid, or even of water, may exert such an action 
(not chemical, I presume, but physical), and fix upon glass any 
design at first traced upon the layer of wax. The search for the 
remaining substances above mentioned was unsuccessful, and 
they were therefore presumed to be absent. 
I will now proceed to state the results which the analysis of 
these brines has afforded me, premising them simply by naming 
the sources from which they were derived. I. Anderton brine, 
from the pit of Lord Stanley of Alderley. IJ. Marston brine, 
from the works of the executors of the late C. W. Newman, Esq. 
III. Winsford brine, from the shaft of Messrs. Kay and Son, 
IV. Wheelock brine, from the works of Mr. Blackwell. 
I. Anderton Brine. 
Specific gravity (August) . . 1:2048 
Temperature of brme .. . oes 
Reaction . . » » » «+ feebly alkaline. 
* Fresenius, Quant. Analysis, p. 345. 2nd Engl. edit. 
+ I accounted for this at first by imagining that a thin film of wax might 
be impressed by the needle upon the glass, which was not immediately 
removeable by the first cleansing. 
t Comptes Rendus, March 30, 1857, p. 679. 
Phil, Mag. 8. 4, Vol, 14, No, 95, Dec, 1857. 2 
