Scientific Intelligence. 



II. Geology an^d Natueal History. 



1. On the Mineralogy of Eozoon Ganad^nse. — Dr. Robei:t 

 Hoffmann of Prague has submitted to chemical and mhuralcui 

 cal investigation the Eozoon Canadense, found at Raspeiiau ii; 

 Bohemia, {Jour, filr prakt. Chemie, May, 1869). He describes tlx 

 Eozoon mass as having a superficial resemblance to that vi' ("ana 1;;, 

 appearing in waved or concentric bands, oval in form, or tl^i i 

 irregular acervuline aggregates. In the oval banded p r 

 the shell of the Eozoon, a nearly pure, finely granular calcite, * 

 separated fi-om the mineral representing the sarcodc, wlii 

 described by Hoffmann as a cast of the soft parts of the K •. 

 formed through infiltration of watery solution either dniiiiu - 

 growth or immediately after the death of the animal. It is v. j 

 culiar silicate, tine-grained, grayish-white and soniewliat traiiMn 

 cent, the analysis of which is given below, (I). Associated witi. 

 this is a finely granular dolomite, destitute of any traces of ov- 

 ganic structure, which sometimes appears to have served a^ a 

 center or point of attachment to the growing Eozoon. In otlier 

 cases, however, broken fragments of older Eozoon liad served ;i- 

 nuclei, and become surrounded with a fresh growth. These lua- 

 terials, which constitute what Hoffinann has described as v::< 

 Eozoon reef, are associated with two other silicated minerals. ' 

 of these, allied to fahlunite, has a specific gravity of i'-'^' 

 grayish-brown or greenish-black in color, dull, or with a som« 

 fatty luster, and nearly opaque. This substance, whose air 

 is given under II, forms nearly parallel streaks in the central j : 

 of "the Eozoon reef, and moreover surrounds it, intersecting :n.i 

 wrapping around the Eozoon mass in multiplied layers, a Hne or 

 more in thickness, which are interlaminated with a light green 

 mineral, transparent, with a somewhat vitreous luster, and a 

 density of 2-56. It is a hydrous silicate (III), allied to picrosmine 

 and is more or less penetrated by magnesite. 



Silica, 



5;^-388 



36-425 



52-677 



Alumina, 



10-521 



32-944 



1-260 



Ferrous oxide, 



10-091 



20-140 



1-011 



Magnesia, 



11-127 





30-414 



Lime, 









Potash, 





2-721* 



7-900 



Soda, 



2-094 







Water, 





7-092 



11-865 













100638 



100-000 



99-360 



i band of Eozoon rocks at 



Raspenau lies 



1^:^?., 



schistose rocks beneath, and overlying beds of granuJ 

 some of them grayish white, and others blackish from an aam^^^ 

 ture of carbonaceous matter. One of these gave to analysis . 

 of carbon, 2-332 of insoluble matter, and 4-708 of carbonate 



