88 THE OCEAN FLOOR 



where his son Gustaf Arrhenius worked upon the core 

 material from the eastern Pacific Ocean. Gustaf Ar- 

 rhenius' work will be specially dealt with in the next 

 chapter. 



The analysis of the iron-group elements, the ferrides 

 iron, manganese, nickel, and titanium, which are of 

 special interest in the composition of the deep-sea sedi- 

 ments, was largely carried out in Goteborg by H. 

 Rotschi and R. Berrit of the Departement de Recherches 

 Outre Mer in Paris, with the aid of microchemical 

 methods. In addition, certain cores were analyzed by 

 spectrographical methods in Stockholm by S. Lander- 

 gren. A mineralogical study of a number of cores was 

 carried out in Sweden by Otto Mellis of Stockholm, 

 E. Norin of Uppsala, and more recently by K. Fredriks- 

 son in Goteborg; in Paris by A. Cailleux and S. Duplaix; 

 and in Gottingen by students under that master of sedi- 

 mentology, C. Correns. A special interest adheres to the 

 radioactive elements in the sediments. Measurements of 

 radium were carried out in Goteborg, largely by Viktor 

 Kroll, formerly of the Institut fiir Radiumforschung of 

 Vienna; uranium determinations were made by F. 

 Hecht of Vienna; and ionium and thorium measure- 

 ments by E. Picciotto and his staff in Brussels. 



The very important microbiological work on the 

 forams present in the samples was undertaken by W. 

 Schott of Hannover, Phleger and his co-workers in 

 Scripps Institution of Oceanography in La Jolla, Wise- 

 man and C. Ovey of the British Museum in London, 



