474 Phillips — Vanadium in Sedimentary Rocks. 



from the Bay of Naples by M. Henze, 1 to the amount of 

 18-5 per cent of V 2 5 of the chromogen. This vanadium 

 content of the blood does not seem to be a characteristic 

 of all acidians, as two species from the Tortugas yielded 

 no vanadium, neither did two other species of holothu- 

 rians yield vanadium. 



These two species in which vanadium has been found 

 in considerable quantities are widely separated in the 

 scale of animal life, one being a Chordata and the other is 

 an Echinoderm, indicating the possibility of other forms 

 which may use vanadium as an oxygen carrier in their 

 vascular system. 



The source of vanadium in sedimentary rocks and coals 

 has always been somewhat of a puzzle, and while we have 

 no way of determining the density of holothurian life in 

 the past or whether the use of vanadium physiologically 

 was developed paleontologically early or late, holothu- 

 rians very similar to the recent species are present in the 

 Jurassic of Europe, and according to Walcott they 

 existed in the middle Cambrian shales of British 

 Columbia. 



It does not seem impossible that such forms as 

 SticJcopus mobii concentrating vanadium to the amount 

 of 0-12 per cent by weight of their dried tissues, living in 

 shallow waters in large numbers, where sediments were 

 collecting or limestones were forming, that this vanadium 

 content of their tissues, at death, could easily be fixed and 

 held as a constituent of the sedimentary rocks thus 

 formed. 



The fixation of vanadium in the sediments of the Tor- 

 tugas would be a simple matter, as there is an excess of 

 calcium carbonate always present and in the presence of 

 which, vanadium salts are practically insoluble. 2 Vana- 

 dium also forms many salts with calcium, some of which 

 are soluble in water and others are difficultly soluble, but 

 all are practically insoluble in slightly alkaline waters, 

 such as seawater, and in the presence of calcium car- 

 bonate. 



A second possibility of the fixation of vanadium under 

 the above conditions is the presence of hvdrogen sulphide, 

 which is constantly liberated in the slimes of the man- 

 grove lagoons and shallows. This in a slightly alkaline 



1 Z. Phys. Chem., 79, 223. 



2 Notestein, F. B., Econ. Geology, 13, 50. Origin of Uranium and Vana- 

 dium ores. 



