172 THE AMERICAN MONTHLY [June, 



of Diatomacefe, but I find records of only the following. 



Hofman gives the analysis of the earth from Bohemia 



in the Journal fur Practische Chemie, 1864, thus : 



(1) (2) (3) (4) 



Aiumonia 03 .01 .34^ 



Potash 02 .30 .24 [- .40 



Soda 30 trace trace] 



Magnesia .43 .36 05 



Lime 41 .44 .64 trace 



Alumina, Ferric Oxide HI 5.40 5.60 .!)! 



Sulphuric acid 12 trace .54 



Phosphoric acid 24 trace trace .19 



Organic matter 4.20 I.IW 13.20 15.45 



Water 13.30 10.f)0 7.00 6.00 



Silica 74.20 80.30 72.60 77.00 



99.63 99.08 100.52 100.00 



It is at Kutschind, near Bilin, Meistersdorp, Luisa 

 spring in Franzenbad. No. 1 is from the upper layer 

 Bilin ; No. 2 is from the lower layer Bilin; No. 3 is from 

 the Meistersdorf, and No. 4 is from Franzenbad. 



These are all from the iceberg period, geologically. 

 No. 1 of the " tripoli," as it is called, has a density of 

 1,862 ; No. 2, of 1,944. That is to say, it is nearly twice 

 as heavy as water. 



In the " Kiesulguhr zu Franzenbad," Ehrenberg dis- 

 covered in 1838, what he called Cocconeis ? clypeus. It 

 was afterwards, in 1841, called Campylodiscus clypeus, 

 and was also found at Santa Fiore, Italy. This also be- 

 longs to the iceberg period. He also found, in the 

 Franzenbad deposit, Navicula bohemica and N. sculpta. 

 These are both varieties of N. amphisbfena of Bory de 

 St. Vincent, 1826. Ehrenberg calls it N. ventricosa, 

 1830, and Kutzing calls it Frustulia depressa. It is not 

 a Navicula, but a Neidium of Pfitzer. 



W. Habirshaw analyzed the electrosilicon of Virginia 

 City, Nev., and found it to contain : 



Silica 81.08 



Water, volatile at a red heat 18.44 



Loss 48 



100.00 



