THERMOMETRICAL OBSERVATIONS AT POINT BARROW. 159 
of metallic bodies by electricity ; in the course of which he had shown that’ 
in many instances, as in the decomposition of a solution of sesquichloride of 
chromium, the deposit upon the negative electrode could be made to assume 
the metallic form by reducing the surface of this plate to dimensions consi- 
derably smaller than those of the positive electrode, a result probably owing 
in part to the secondary decomposition produced in the limited portion of 
liquid around the wire, whereby the sesquichloride was reduced to the proto- 
chloride of chromium and subsequently the metal itself was deposited. This 
view was rendered probable by observing the effects obtained during the 
electrolysis of sesquichloride of iron, in which these successive steps could be 
distinctly observed. In cases in which, like the chloride of manganese, the 
compound was already in the condition of protochloride, it was unimportant 
whether or not the negative electrode presented a smaller area than the 
positive electrode. Attention was called to the fact pointed out by Faraday 
of the non-existence of more than one electrolyte in a multiple series; thus 
in the case of the two chlorides of tin, the fused protochloride is an electro- 
lyte, but the bichloride, although a liquid at ordinary temperatures, is not an 
electrolyte if anhydrous. Yet the bichloride when dissolved in water, itself 
also not an electrolyte, conducts freely; and a similar result is obtained in 
other analogous cases. 
Referring to the decomposition of salts in solution, the bearings of elec- 
trolysis upon Davy’s binary theory of the composition of salts were briefly 
alluded to, and some of the difficulties attending the adoption of this theory 
in the case of the subsalts were mentioned; these facts, taken in conjunction 
with those already alluded to in the case of the bichloride of tin, leading the 
author rather to the view that a salt is to be regarded as a whole, susceptible 
of decomposition in various modes (just as a crystal may admit of cleavage 
in two or three different directions according to the method in which the 
force is applied), and therefore admitting of representation under two or three 
different rational formule, each of which may, under particular circumstances, 
be advantageously employed. 
Results of Thermometrical Observations made at the * Plover’s’ Winter- 
_ _ ‘ng-place, Point Barrow, latitude 71° 21' N., long. 156° 17' W., 
_ 1852-54. By Joun Simpson, Esq., R.N., F.R.CS., F.R.G.S.5 
__ - Surgeon of H.M.S8. * Plover,’ 
. [With a Plate.] 
Ar p. 331 of the ninth volume of the ‘Royal Geographical Society’s Journal,” 
1839, Sir J. Richardson, in reference to Sir David Brewster’s discussions of 
an hourly register of the temperature at Leith Fort, says:— : 
“Convinced of the importance of investigating the phenomena of diurnal 
temperature in various latitudes, I have thought that a discussion of the 
_ thermometrical observations made on Sir E. Parry’s several voyages would 
_ be a service rendered to science.” Following the lead thus indicated, it has 
appeared to me that the results of the observations made at Point Barrow 
would be a valuable though small addition to those given by Sir J. Richard- 
son, to whose form of tables I have adhered, only making additions, as the 
_ means of the decades or three divisions of each month, where I thought this 
_ could be done without marring the original purpose of the table. 
_ The observations now offered were made with great accuracy, and possess 
_ the advantage of having been registered every hour at one spot from the 3rd 
of September 1852 to the 7th of: August 1853, and for a few days before 
