Scientific Intelligence.— Geology. 389 



8. Tremolite Jound in Teesdale. — In a granular limestone, 

 a member of the lead measures, near Caldron Snout, Teesdale, 

 Durham, I found, in 1829, tremolite, in small radiated crystals 

 of a greyish colour. — W. C. Trevelyan. 



GEOLOGY. 



9 Salt Spring of Birtley in Durham. — I have lately ex- 

 amined some water from the salt spring at Birtley in the county 

 of Durham, and have ascertained that it contains both iodine 

 and bromine. — The specimen was procured for me in Febru- 

 ary : I found its specific gravity at temperature 60° to be 1.072, 

 and calculating according to Kirwan's formula given in Thom- 

 son's Chemistry, 1072 — 1000 x 14 = 100.8 — saline contents 

 in 1000 parts of this water. I evaporated to dryness, but with- 

 out expelling the water of crystallization, 1000 grains of it, and 

 found the residuum to weigh lOB grains. Mr Winch, in the 

 Transactions of the Geological Transactions, vol. 4th, mentions 

 that this spring produces 26400 gallons in 24 hours ; and that 

 when analyzed by Mr Woods, it was found to contain in 1000 

 grains, muriate of soda 87 ; muriate of lime 43 ; muriate of 

 magnesia, carbonate of lime, carbonate of iron, and silica, 4; 

 = 131 grains, which is considerably more than I found in it ; 

 but perhaps it may vary at different seasons in the quantity of 

 saline matter. — A remarkable circumstance with regard to this 

 spring, and some others in the same district, is, that it occurs 

 in the coal-formation far below the well-known saliferous or new 

 red sandstone. — W. C. Trcvelyan. 



10. Tieshayes' New Classification of the Tertiary Formations. 

 — Mr T. J. Torrie informs us, that Deshayes classes the whole of 

 the tertiary deposits at present known, from the simple consider- 

 ation of their fossils (of which he possesses 3000 species) into 

 three groups. The most ancient embraces the London and Paris 

 basins, and the tertiary strata of Belgium, and contains more 

 than 1200 fossil species, of which only 38 are analogous to the 

 shells actually living. The second embraces the whole tertiary 

 deposits of Bordeaux, Dax, Touraine, Anjou, of the south-west 

 of France in general ; the inferior part of those of Montpellicr, 

 and probably the Calcairc ma'lon of Marcel dc Scries ; those 



