604 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, : ; : H — 06-00 
Si. = 65-74 
Al: = -02-50 
Silicates not taken up by hydrochloric acid, = 63-40 rll Saye 
Mg = 00-78 
Alk = 01-99 
63-40 
Sesquioxide of iron, . : ; 3 Fe — 09-00 
Alumina, . : 4 j Al = 09-30 
Magnesia, . : ; : a Mg = 03-00 
Potash, P ‘ j : e K = 07-60 
Chlorine, a trace. 
Loss, . : : 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 Terres of Nebraska, are interesting and remarkable, as showing the change 
which they have undergone during the long period of interment. 
PART OF LEG-BONE OF OREODON. PART OF SCAPULA OF PALZOTHERIUM. 
Water of absorption, ‘ : H = 2-70 : : ‘ 2-50 
Organic matter burnt off by ignition, ; = 2:50 : : ; 3:20 
Phosphoric acid, . P — 36-77 32-00 
Carbonic acid, ‘ : ‘ Cc =. 8-00 : ‘ 4-20 
Fluorine, . F = 3:20 ; ‘ ‘ 3°40 
hint, On =< 4808 Combined With Pci. ea00 
Silica, , ; : ? Si= 840 Ca  « a ee 
Trace of Fe and Mn, ji e Ca bh «FF — 8:66 
a8 “«Si(?) = 0-80 
Fe . "4-50 
dee : 0-70 
Mg . 0-90 
Mn . . : 0-80 
Na . . 2-04 
Fe Siinsoluble, 1-64 
Si dissolved by HCl, 0-30 
Loss, - : 051 
100-50 100-00 
* The excess is perhaps due to the 5 blip of oxygen by the calcium combined with the fluorine. 
