172

Dr D. remarks bad conductor of Heat do of Electricity

Does not iron, combined with nickel & cobalt (meteoric) resist oxidation? - Mem Sir W. Pistone

It is clear to me there are laws of solution & deposition under great pressure. (? fact!) unknown to us.

M. Chladni. - on meteoric Mexican stone. Journal des Mines 1809. No. 151. p. 79[-80].

[Au catalogue des météores, à la suite desquels des pierres ou des masses de fer sont tombées.]

 

170

Geology of Guanuaxuato. Clay slate. passing into talcose & chloritic slate with beds of syenite & serpentine dipping to SW at 45° to 50° - covered by conformable greenstone porphyrys & phonolites do amphibole quartz & mica very rare. ancient freestone & breccia is the same with that on surface of plains of Amazon, no relation - there is more modern breccia, chiefly owing to destruction of porphyries. whereas other to ancient rock. - this Nº 2 - superimposed on Nº 1 even No. 2 might be mistaken for Porphyry

 

175

Guanaxuato, which has yielded the most metal, where the direction of ravins, and the slope of the mountains (flaqueza del Cerro) have been parallel to the direction & inclination of the vein"

 

at Zacatecas the veta grande has same direction as Guanax - the other E & W - veins richest not in ravins or along gentle slopes but on the most elevated summits, where mountains most torn. (anticlinal line?)

 

Mines of Catorce (Principal veins) 25° to 30° to NE. vein of Moran 84 NE. of Real del Monte 85 to S. // Tasco 40° to NW (afterwards said to be all with some exception directed NW & SE)

 

176

Vol III

Mexican Cordillera "immense variety of Porphyries which are destitute of quartz, & wh abound both in hornblende & vitreous felspar"  p. 215

Same metal in Tasco vein in Mica Slate & overlying Limestone

Balls of Silver ore occur in do veins.

At Huantajaia Humboldt says, mur of Silv Sulph. of do galena quartz, Carb. of Lime. accompany. - Ulloa has said silver in the highest & gold in the lowest. Humboldt states that some of the richest gold mines on ridge of Cordillera near Pataz, also at Gualgayoc. where many petrified shells

[Alexander von Humboldt. Political Essay on the Kingdom of New Spain, vol. 3.]

177

Bougainville says P 291

The Fuegians treat the "chefs d'æuvre de l industrie humaine, comme ils traitent Ies loix de la nature & ses phenomenes."

Ulloa's Voyage, Shell fish purple die, marvellous statements on, Vol I, P. 168.

on coast of Guayaquil, same as Galapagos

no Hydrophobia at Quito. P 281. do do

Australia, C. of Good Hope. Azores Isds [nor at St Helena.

Humboldt. New Spain Vol. IV. p. 58

At Acapulco earthquakes are recognized as coming from three directions. from W. NW & S. - last to Seaward