110 
TIIE VOYAGE OF H.M.S. CHALLENGER. 
magnesia liquor = 49 - 4 x 
S‘ = 5172x 
The alkalinity of the finished 
solution determined ana- 
lytically, and found = 537 x 
A»l >pt ing this latter number, and assuming the 1 ‘ alkali ” to be simply RHC0 3 # free from 
II ,('( i . we have for the carbonic acid per litre 107‘5 mgrms. The solution was shaken n 
times with air, as usual, and the carbonic acid in the resulting liquor determined. 
Found for 
107 a — 95*9 = 1 16. Hence about , l 0 th of the whole, or £th of the loose, carbonic acid 
ha«l been eliminated by eight shakings with air at the ordinary temperature. 
250 c.c. of distilled water were heated to boiling, coloured by aurine, and exactly 
neutralised by the requisite few drops of the Standard hydrochloric acid. 7 grms. of a 
■ rtain ehlnride of sodium and 3’44 grms. of a certain Epsom salt were now dissolved in the 
liquid, and the solution again titrated. 038 x^ mgrms. were required for neutralisa- 
tion. From these two salts — 
Solution I. was prepared, by dissolving 56 grms. of the chloride of sodium and 
27 ’5 gnu-, of the Epsom salt in water, boiling, filtering, and diluting to 1 litre. 
S -lution II. A freshly made solution of bicarbonate of magnesia was diluted, so 
that, by intention, 1000 c.c. = 100 x ^ - 9V ' p mgrms. It was found by actual titration, 
that 1000 e.r. = 99 0 x mgrms. Equal volumes of these two solutions were mixed 
tie r, and tie- alkalinity <>f tin- mixture determined by titration. 
Adopting the latter number, and assuming lioth the magnesia- and the carbonic acid 
!' nt only a 111 ICO*, we have for the carbonic acid, 100'4 mgrms. per litre. 
This liquor was shaken three times with air, to eliminate the free carbonic acid, and from 
■“ • i ur d volume - of the r< -tilting liquid the carbonic acid eliminated (as far 
- - it in Cla--eii's apparatus in a current of air, with cither chloride 
of barium or hydrochloric acid, as shown in the following table: — 
Carbonic acid mgrms. per litre (lost) 
n = 
o 
4. 
98-9 
6 . 
977 
8 . 
95-9 
Elimination of Carbonic Ac'ul from Artificial Sea-Water by Chloride of Barium. 
mgrms. 
By analysis, 1 000 c.c. = 50 20 x j ““ 
Wh> tf “ It “tan da for on equivalent of metal ; i.e., for Nu, % Ca, &c. 
