of Serpentine, 8(C. in the Apennines. 207 



Plate Vr. 



L. Lagonis properly so called, or small lakes of muddy 

 and hot water, that traverse with impetuosity and violence 

 the aqueous and sulphureous vapours containing boracic 

 ' acid. 



Fig. 4. Disposition of magnesite in the natural section 

 of the hill of Castellamonte, near Turin. 



A. Diluvium or alluvium (Terrain de transport) com- 

 posed of rolled pebbles in its upper part, and of reddish 

 sand in lower portion. 



B. Mass of pale green disintegrated serpentine, in 

 which veins of magnesite wind and inosculate. 



a. a. a. Veins of magnesite. 



b. Chalcedony in mammilated plates, &c. in the midst 

 of some of these veins. 



c. Veins of green concretioned hornstone. 



d. Nodules or blocks of brownish green felspathic 

 serpentine, scarcely altered in the centre, and decomposing 

 in concentric layers. 



