172 THE AMERICAN MONTHLY [Jurip, 



of Diatomacese, 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 : 



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 Coccoueis ? 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. amphisbjena of Bory de 

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

 1830, and Kutziug 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 



