REPORT ON THE COMPOSITION OF OCEAN-WATER. 
59 
Now, according to my experiments (by formula) — 
4817-5 4W17 5 — X-^i7-5 = 1 '38196y ; 
whence 
or 
The Norwegians’ result is 
or, writing 
According to my experiments, 
4 S 17 -5 1 _1'38196 % 
t W 17 , 
4 w 17 , 
1 7-5817-5- 1 Q° 0 _i .38369 
% 
1-3716, 
AS for 17-5817.5 — 1000 . 
X = (AS)+ 1-3837 . 
According to the Norwegians’ experiments, y = ( A S) -r- 1 - 37 1 6 
i.e., taking my result as the standard, the Norwegians overrate their chlorines by about 
^ = 0-0087 of their true values. But this is not doing justice to the relative correctness 
of their results ; they used different methods from mine, both for the determination of the 
chlorine and of the specific gravity,* and their formula may be more correct than mine 
for the reduction of their y’s and S’s to one another. 
The primary and principal object of my investigation was to formulate the mathe- 
matical relation between y on the one hand and a given coujde of values of t and 4 S on 
the other. And from the values for r given at the foot of Table II., it would appear 
that my equation 
4 s,- 4 w, 
^ a + bt + d 1 2 
with the calculated values substituted for a, b, c, does this with a very fair degree of 
precision. But part of this precision probably is bought, so to say, at the expense of 
some of the exactitude which my experiments, Series I. and II., might claim as deter- 
mining the relative volumes, at different temperatures, of the respective two kinds of 
sea-water. This we must keep in view when we now proceed to utilise the equation, as 
formulating, in reference to a sea- water of given salinity (i.e., for y = constant), the 
relations between volume and temperature. 
Of the several researches on the thermic expansion of sea-water, I have utilised the 
following for checking my results in the sense referred to : — 
(1) Hubbard’s ; or rather a table giving the volumes of “ Ocean- Water ” at O', 1°, 
2° . . . 30° Cent., in terms of the volume at 15°"56 C. or 60° F., which Mr. Buchanan 
has calculated from a table in Hubbard’s original memoir, which gives the volumes 
* This they determined by means of hydrometers. 
