92 



Carbon-Dioxide Content of Sea-Water at Tortugas. 



Chloride. — The chloride was titrated with silver nitrate, using 

 potassium chromate as indicator, and the density of the water was 

 calculated with the aid of Knudsen's tables. 



u 



-, 0.094 



.092 



.090 



.088 



.086 



Cloudy 



Ram 



N.wind Cloudy Cloudy Rough Fair Fair Ram 



Fig. 1. — Total carbon dioxide and time of day. 



H-ion concentration. — The Ph values were estimated colorimetri- 

 cally by comparison with a set of standard tubes very kindly loaned 

 by Professor J. F. McClendon. 



Excess base. — The excess base was obtained by titrating 100 c. c. 

 portions with 0.02 normal sulphuric acid, using methyl red as indi- 

 cator and blowing out the carbon dioxide by means of pure air for 



Table 1. — Determinations on Sea-Water at Loggerhead Key, Tortugas, June 1919. 



[t, temperature, °C.; CI, chlorine, grams per kilogram; D, density; Ph, hydrogen-ion concentra- 

 tion expressed as — log [H + ]; Alk., excess base, in terms of a normal solution, or alkalinity 

 titrated with acid, using methyl red and blowing out CO2; CO2, total, gram per liter.] 



Date, time, and condition of water. 



June 10, 

 11, 

 11. 

 12. 

 13, 

 13, 

 13, 

 13, 

 14, 



14, 

 14, 

 15, 

 15, 

 16, 

 16, 

 16, 

 16, 

 16, 

 17, 

 17, 



17, 

 17, 

 18, 



18 

 18, 



3^3CP p.m.; cloudy. . 

 12 noon; fair 



5''30"'p. m.; cloudy. . 

 12 noon; after rain. . . 



GMS" a.m. ; after rain 



9 50 a.m.; cloudy. . , 

 12 50 p.m.; cloudy. . 



4 10 p.m 



9 45 a.m.; after rain 



and wind 



3M5™ p.m.; wind. . . . 



5 15 p.m.; wind. . . . 



6 30 a.m.; wind. . . . 

 11 a.m 



7''10™ a.m.; fair 



8 15 a.m.; fair 



11 a.m.; fair 



4''15™ p.m.; fair 



5 45 p.m.; fair 



6 30 a.m 



10 15 a.m.; slightly 



cloudy 



4*^45™ p.m.; rainy. . . 



7 p.m.; after rain. . . . 

 7'' 15™ a.m.; after 

 shower 



11 a.m.; rain 



1 p.m. ; rain 



26.6 

 27.6 



28.2 

 27.4 

 27.1 

 27.1 

 27.5 

 27.6 



27.0 

 27.4 

 27.8 

 26.5 

 26.8 

 26.8 

 27.0 

 27.0 

 28.1 

 27.8 

 27.1 



27.3 

 26.8 

 27.6 



26 8 

 26. S 

 26.6 



CI 



20.01 

 20.00 

 20.05 

 19.90 

 19.28 

 19.90 

 20.07 

 19.96 



19.89 

 19.87 

 20.00 

 19.94 

 19.31 

 19.99 

 20.00 

 19.99 

 20.05 

 19.98 

 19.99 



20.09 

 19.16 

 19.77 



20.04 

 19.81 

 19.73 



D 



02373 

 02339 

 02326 

 02332 



1 . 02258 

 1 . 02342 

 1.02352 

 1.02334 



1.02344 

 1 . 02328 

 1.02333 

 1.02366 

 1.02371 

 1 . 02368 

 1.02359 

 1.02357 

 1.02330 

 1 . 02330 

 1 . 02354 



1.02361 

 1.02239 

 1 . 02308 



1.02370 

 1.02339 

 1 . 02334 



Ph 



8.23 

 8.19 

 8.19 

 8.21 

 8.20 



8.19 

 8.22 

 8.21 

 8.21 

 8.21 

 8.07 

 8.19 

 8.20 

 8.23 

 8.21 

 8.20 



8.18 

 8.20 

 8.19 



8.18 



Alk. 



0.002370 

 . 002368 

 .002398 

 . 002394 

 .002394 

 .002410 

 . 002402 



.002406 

 .002402 

 .002412 

 . 002435 

 .002424 

 .022368 

 .002414 

 . 002440 

 . 002374 

 .002410 

 .002414 



.002396 

 .002306 

 .002326 



.002418 

 . 002400 

 .002374 



CO2 



. 0890 

 .0925 



.0902 

 .0924 

 .0913 

 .0900 

 .0897 



.0881 

 .0863 

 .0873 

 .0910 

 .0869 

 .0904 

 .0896 

 .0888 

 .0873 

 .0873 

 .0928 



.0910 

 .08.57 

 .0893 



.0918 

 .0928 

 .0879 



