506 THE DEPTHS OF THE SEA. [CHAP. X. 
surface-waters. (2) Analyses of waters below the surface ; and 
these last may be again subdivided into (a) fafa and 
(6) bottom-waters. 
Second Cruise 
| Third Cruise . 
The total quantity of dissolved gases in sea-water, whether 
at the surface or below it, was found to average about 2°8 
volumes in 100 volumes of water. 
The average of thirty analyses of surface-waters made during 
the expedition gave the following proportions :— 
Percentage. Proportion. 
Oxygen), =. ..... 25046 100 
Nitrogen 4. > 2+. ( 54°21 216 
Carbonicacid. . . 20°743 80 
1007000 
These were thus distributed over the three cruises, and the 
maxima and minima of each constituent are thus shown :— 
Carbonie 
| 
Average per- Average Oxygen. Nitrogen. Aveta 
centage. proportion. 
analyses. 
| 
Salles Car- Max. | Min. | Max. | Min. | Max. | Min 
Eey- ae bonic 0. | N. |CO,| per | per | per | per | per | per 
Ben | Sen. | acid. | cent. | cent. | cent. | cent. | cent. | cent. 
Number of 
First Cruise . | 19 | 24°47 | 52°95 | 22-58 moO 16 92 | 28°78 | 19°60 | 62°95 | 46°35 | 32°0 | 12°72 
| 
31:33 | 54°85 | 13°82 | 100) 175/ 44 | 37-10 | 25-36 | 59°63 | 60-07 | 24-37] 38-27 
bo 
© 
24°86 | 66°73 | 18°41 100 | 228| 74 | 45°28 | 18°98 | 68°67 | 41°42 | 27°14] 5-64 
It is interesting to remark that surface-water contains a 
greater quantity of oxygen and a less quantity of carbonic acid 
during the prevalence of strong wind. The following is an 
average of five analyses made under such conditions :— 
Per cent. Proportion. General average. 
Oxygem* =. 2: BSG 100 25°046 100 
iINvbropeny (b<e 0. 52787 182 54211 216 
Carbonic acid. . 18°03 62 20°743 83 
In the two cases which presented the remarkable small 
minima of carbonic acid with a great excess of oxygen, the 
water had been accidentally taken from immediately abaft 
the paddles, where it had been subject to violent agitation 
in contact with air. 
