314 PAPERS FROM THE DEPARTMENT OF MARINE BIOLOGY. 



Makin' is given as 20.6569 grams per liter and the specific gravity at 15.5° C. 

 is given as 1.0275. According to Knudsen's tables this content of chloride, 

 with correction for specific gravity, is approximately equivalent to 19.97 

 grams per kilogram of chloride, salinity 36.08 grams per kilogram, and a 



specific gravity (o) of 1.0290. The slight difference between this result 



and the corrected average of results at Fowey Rocks might reasonably be 

 attributed to difference in procedure and in calibration of instruments. The 

 chloride content of standard sea-water sample Pi'/i, 1912, is 19.386 grams 

 per kilogram and the corresponding salinity is 35.02. 



The chloride content of the 7 most strongly concentrated bottom sam- 

 ples collected by Mr. E. W. Shaw off the mouth of Mississippi River ranged 

 from 19.81 to 19.99 grams and averaged 19.88 grams per kilogram.- This 

 average corresponds to a salinity of 35.91 grams per kilogram. 



The salinity of a sample collected by Dr. T. W. Vaughan oft" the west 

 side of Andros Island in the Bahamas is definitely higher than the salinity 

 in general in Atlantic Ocean, and it is also higher than that on the east side 

 of the Island. The submarine flat off the west side of South Bight is more 

 than 60 miles wide"^ and the maximum depth within this distance is 3I 

 fathoms. It is therefore not surprising that the salinity should be some- 

 what higher there by reason of excessive evaporation as compared with that 

 on the east side, where the submarine shore flat is only about 4,500 feet w ide, 

 beyond which there is a steep drop to 1,000 fathoms. 



'Makin, C. J. S., On the composition of the Atlantic Ocean: Chem. News, vol. 77, pp. 155, 171, 1898; 

 quoted by F. W. Clarke, The data of geochemistry: U. S. Geol. Survey Bull. 616, p. 123, 1916. 



-Shaw, E. W., The mud lumps at the mouths of the Mississippi: U. S. Geol. Survey Professional Paper 85-b, 

 pp. 11-27, 1914- 



^Personal communication from Dr. Vaughan. (See discussion by him on page 274 of this volume.) 



