PREFACE 



the central North Atlantic and the Caribbean Sea — regions 

 not previously investigated. The data and their discus- 

 sions are valuable contributions to our knowledge of the 

 chemical conditions in different regions at various 

 levels. 



It should be noted that this report contains no refer- 

 ences to literature published later than the early part of 

 1935, at which time the final revision of the manuscript 

 was made. It is realized, however, that more recently 

 the results of a number of Qceanographic investigations 

 dealing with both the Atlantic and the Pacific oceans, 

 as well as with adjacent marine regions, have been 



published. As a consequence of these recent investigations 

 it is possible that some of the generalizations or conclu- 

 sions based on the Carnegie and earlier data will need to 

 be modified, but it is felt that the results of the observa- 

 tions and analyses made by the Carnegie are reliable and 

 comparable with those subsequently reported. 



The present volume is the tenth in the series "Sci- 

 entific results of cruise VII of the Carnegie during 1928- 

 1929 under command of Captain J. P. Ault." 



J. A. Fleming 

 Director, Depai-tment of Terrestrial Magnetism 



