170 S. F. Sharpies on Bredgings from the Gulf Stream. 



My experiments failed to show more than the slighest traces 

 of fluorine and I could only find silica in one or two instances 

 and then in mere traces. There were also traces of iron and 

 magnesia. 



The above analyses are interesting from several points of 

 view. In the case of the bone we have first a replacement of 

 tri-calcic phosphate by calcic carbonate. The total percentage 

 of lime having diminished, while iron, which was present only 

 in traces in the original bone, exists in considerable quantity. 



In regard to the replacement of the phosphate by carbonate 

 one or two explanations may be offered. Calcic phosphate, as 

 shown above, is soluble to a considerable extent in solutions of 

 organic matter. This will account for the removal of part of 

 that salt. Then again during the decomposition of the gelatine 

 of the bone ammonic carbonate would be formed in consid- 

 erable quantities. The cartilage of bone containing about 18 

 per cent of nitrogen which would be equivalent to about 123 

 per cent of ammonic carbonate, alkaline carbonates decompose 

 calcic phosphate more or less completely ; they also precipitate 

 calcic sulphate from solution ; forming in both cases calcic 

 carbonate. We should therefore have ammonic sulphate and 

 phosphate going into solution while calcic carbonate would be 

 deposited. 



We have now remaining only the oxide of iron to be 

 accounted for ; the silica being mostly in the insoluble state 

 may be regarded as adventitious. It is a difficult matter m 

 absence of any data concerning the amount of iron in the vva- 

 ters or bottom of the Gulf Stream or Gulf of Mexico to do any 

 thing more than offer a possible explanation of the presence oi 

 so large a quantity of this element. Yeiy few of the analyses 

 of sea water give more than a trace of iron. The waters of tne 

 open ocean are almost entirely free from it. But those ot in- 

 closed seas, such as the Black and Mediterranean, contain a con- 

 siderable amount. It is also contained in river water, it being 

 absent m but few of the analyses of such water that have been 

 given. '' 



Now we have in the case of the Gulf of Mexico a sea that is 

 tor all practical purposes surrounded by land, and we haveab" 

 large nvers carrying down in all probability great quantities ^ 

 iron. Ihis coming in contact with decomposing organic x^^^ 

 vdl be converted at first into carbonate and deposited; it^ 

 w .^.^l^^^ly changed into sesquioxide. This is achang 

 OTids '^ ^^"^^^^^^^ is slowly going on at the bottom of nio^ 

 o\I^^ f^^^''' ^^- 2, of rock gives an instance when tbi3 

 change has gone further, and tl.e phosphoric acid has become 

 much reduced in amount, both l)y he sLlvcut action of the or- 



