REPORT ON THE COMPOSITION OF OCEAN-WATER. 
129 
with the alkalinity of the water as it was when titrated, gives, for the original alkalinity 
the high value of 0'2911. But part of the deposit may have been sulphate of lime. 
The water was collected at Station 2 near the Canary Islands. 
[260]; a bottom water collected on the 25th of April 1873, at Station 38 (see page 
123). The bottle contained a considerable quantity of a sandy deposit. The alkalinity, 
which in the table is given as being 55*26 mgrms. per litre, was determined in only 97 c.c. 
of the filtered water. The alkalinity of the residue was determined, and found equal to 
41 ’66 mgrms. per 250 c.c. of the water still present in the bottle at the time. Unfortunately 
it was forgotten to note down the volume of the water remaining, and the capacity of the 
bottle as an approximation to the volume of the original sample. Assuming that volume 
to have been 2 litres (it certainly was not more), then the residue, supposing its carbonate 
of lime and magnesia to pass into the water, would have added at least some 21 mgrms. 
to the alkalinity per litre. The water in the bottle, therefore, we should say, was at the 
maximum of alkalinity which it could possibly have attained by stagnating in its natural 
situation. 
No. 492 [276]; a bottom water from Station 169 ; gave the high alkalinity of 75 *88 
mgrms. per litre, or (P2108 per 100 of salts (see page 126). The bottle contained a 
large deposit of light mud. The mud was not examined, but in the filtered water the 
lime and magnesia were determined, as in the case of No. 5 [204], by duplicate analyses. 
Found per 100 of Chlorine. 
No. 492. 
Average Deep-Sea 
Water. 
Lime, 
3-515 
3-031 
Magnesia, 
11-147 
11-212 
Taking the excess of lime and the deficiency in magnesia as corresponding both to 
carbonate gained and lost respectively, and starting from the value 0'152 as representing 
the normal alkalinity of bottom water ( vide infra), the alkalinity of this water should 
be equal to 0*3229 instead of 0*2108 as found. This shows that our assumption does 
not hold ; part of the additional lime, probably, is sulphate taken up from the mud after 
bottling. 
No. 31 [221]; a surface water collected at Station 12, as stated on table, page 43. 
[It is not on the Table of Alkalinities.] This water contained a large crystalline deposit, 
consisting mainly of the carbonates of lime and magnesia. Capacity of the bottle up to 
upper edge of deposit, i.e., presumable original volume of the sample =1415 c.c. 
(PHYS. CHEM. CHALL, EXP. — PART I. — 1884.) A U 
