NARRATIVE OF THE CRUISE. 
979 
will be seen that, out of seventy-two surface waters examined, only seven contained more 
than the amount of carbonic acid eliminable by this method. Of these seven cases, three 
were waters at temperatures above 70° F., and three at temperatures below 35° F. On 
the whole, less carbonic acid was found in warm than in cold latitudes. Omitting two 
abnormally high but not incorrect results obtained in the tropical sea between Fiji and 
Torres Strait, the following table shows the mean amount of carbonic acid per litre in all 
the surface waters arranged according to the temperature of the water in situ : — 
Number of Cases taken 
Account of. 
Temperature Interval, 
°C. 
Carbonic Acid, Milligrammes 
per Litre. 
20 
25°-0 to 28-7 
35 '88 
15 
200 „ 25-0 
37-18 
10 
15-0 „ 20-0 
42-68 
8 
10-0 „ 15-0 
43-50 
8 
5-0 „ 10-0 
47-21 
9 
-1-4 „ + 3-2 
53-31 
The observations made on waters from different depths are averaged in the following 
Table 
Depth in Fathoms. 
Carbonic Acid. 
Grammes per Litre. 
No. of Determina- 
tions of C0 2 . 
Average Temperature 
of Water. 
Surface. 
0-0426 
73 
°C. 
25 
0-0337 
2 
50 
0-0488 
10 
100 
0*0436 
5 
14-6 
200 
0-0446 
8 
13-0 
300 
0 0440 
4 
6-9 
i 400 
0-0411 
10 
5-1 
800 
0 0422 
7 
2-5 
over 800 
0-0446 
7 
1-5 
Bottom 
0-0474 
54 
