346 



EECEEATIVE SCIENCE. 



the tertiary coals, from their geological posi- 

 tion in the tertiary series of beds, and thus 

 they are pointedly distinguished from the 

 true and pure coals of the carboniferous 

 series of rocks. There are many kinds of 

 them in different countries ; some which 

 merely exhibit occasional indications of vege- 

 table structure, and generally form through- 

 out a stratified mass of a dark colour, pos- 

 sessing an earthy fracture, are hence termed 

 earthy brown coals. Such is the coal of 

 Meissner, near Cassel, in Germany. Other 

 varieties, in which the fracture is shelly (con- 

 choidal), and the structures more danse, are 

 called conchoidal brown coals, or pitch coals. 

 These deposits are frequently found near the 

 surface, but in other situations at considerable 

 depths. Tertiary lignite abounds at St. Gall, 

 in Switzerland, and in a bed of brown coal, 

 near that place, a singular and new species of 

 combustible mineral (Scheererhite) has been 

 found. The tertiary coals in the canton of 

 Zurich are remarkable for many bones of 

 mammifers, which are said to have been dis- 

 covered amongst them, associated with which 

 are reported bones of the mastodon. All 

 these circumstances are interesting in con- 

 nection with the origin and geological posi- 





} 



ill" 



Fig. 1. 



tion of the comparatively modem and im- 

 perfect coals. 



Figure 1 displays a transverse section 



of the German brown coal, in which the 

 woody fibres are cut through by the section 

 transversely to their long axis. In com- 



Fia. 2. 

 parison with this we present (in Fig. 2) a lon- 

 gitudinal section (parallel to a radius) of 

 recent coniferous wood of the Pinus strobus. 

 In Fig. 3 is seen part of a transverse section 

 of the same wood, the whole section being of 

 the same character. 



Mr. Nicol refers to specimens from the 

 coals of ]S"ova Scotia, in the collection of 

 Professor Jameson, " one of which," says 

 he, " is a fossil conifer, displaying all the 

 characters of the most perfect recent Ame- 

 rican pines. In the transverse section, the 

 annual layers are well defined, the reticulated 

 (net-like) texture large and perfect, and in 

 the longitudinal section, parallel to a radius, 

 discs occur both in single and double rows. 

 These, as usual, are in some parts very obscure, 

 but in other parts they are very distinct. 

 They are circular, and some of them display 

 at the circumference two concentric rings, 

 and one ring near the centre. In the double 

 rows, as in the recent pines, the discs are 

 placed side by side, and indeed in all its cha- 

 racters this fossil bears a greater resemblance 

 to some of the recent pines than anything of 

 the kind that has hitherto fallen into my 

 hands." The discs spoken of are also con- 

 spicuous in the section (Fig. 2), and the struc- 



