004 



ADDITIONAL CHEMICAL EXAMINATIONS. 



that in the insoluble silicates, which were analyzed by fusion with carbonated alkali, was only estimated 

 by deficiency, and not by actual precipitation. 



An analysis of a specimen of argillaceous oxide of iron, collected by Dr. Norwood on the northwest 

 shore of Lake Superior, resulted thus : 



Water, 



Silicates not taken up by hydrochloric acid, 



Sesquioxide of iron, . 



Alumina, 



Magnesia, 



Potash, 



Chlorine, 



06-00 



= 03-40 



Si 

 Al 



55-74 

 02-50 



Fe = 02-44 



Mg = 00-73 

 Alk = 01-99 

 03-40 



Loss, 



Fe = 09-00 

 Al = 09-30 

 Mg = 03-00 

 K = 07-60 

 a trace. 

 01-70 



100-00 



ANALYSES OF FOSSIL BONES OF NEBRASKA. 



The results of the chemical examinations of the bones of some of the fossil mammalia, from the tertiary 

 formation of the Mauvaises Torres of Nebraska, are interesting and remarkable, as showing the change 

 which they have undergone during the long period of interment. 



TART OF LEG-BONE OF OEEODON. 



Water of absorption, 

 Organic matter burnt off by ignition, 

 Phosphoric acid, 

 Carbonic acid. 

 Fluorine, 

 Lime, 

 Silica, 



Trace of Fe and Mn 



PART OF SCArULA OF PAL/EOTHERIUM. 



II = 



2-70 









2-50 





2-50 









3-20 



p = 



36-77 









32 00 



c 



3-00 









4-20 



1' = 



3-20 









3-40 



Ca = 



48-93 



Combined wi 



th'P 



= 34-00 



Si = 



3-40 



Ca 





" C 



= 5-35 







Ca 





« F 



= 3-66 







Ca 





«Si(? 



) = 0-30 







Fe 







4-50 







Al 







0-70 







Mg 







0-90 







Mn . 







0-80 







Na 







2 04 







Fe Si 



insoluble, 





1-04 







Si dissolved by HC1, 



0-30 









Loss, . 





0 51 





100-50 









100-00 



* The excess is perhaps due to the absorption of oxygen by the cnlcium combined with the fluorine. 



