1870.] 427 [Haack. 



artesian well at Buenos Ayres it was found at the depth of 280 feet; 

 and, probably, this tertiary formation extends below the surface to 

 the Cordilleras- Other sedimentary formations are not known as 

 yet in the Argentine Republic. 



Some volcanic products, namely, Amygdaloid and Melaphyr and 

 also Granite and Syenite wit'h Gneiss and Amphibclis, are found in 

 the La Plata States. Southern Brazil, the Uruguay Republic, the 

 island Martin Garcia at the mouth of the Uruguay, and the chain 

 near San Piedras, are very rich in these rocks. 



Montevideo, or San Felipe puerto del Montevideo, the capital 

 town of Uruguay, stands upon a promontory which consists of gneiss; 

 but the " Cerro de Montevideo," a conical hill one hundred and fifty 

 metres high, consists only in the lower and eastern part of gneiss, 

 the western side and the top being composed of amphibolis which 

 changes into diabas. 



In concluding my paper I will mention one fact which deserves 

 to be better known to the scientific world. It is the occurrence of 

 large masses of meteoric-iron in those extensive northern plains which 

 are called " el Gran Chaco." These plains lie eastward from the Rio 

 Salado, and from the 19th degree extend in the Bolivian province 

 Chiquitos, to the 30th degree of south latitude; and from the 40th 

 to the 45th degrees of longitude westward from Ferro. The rivers 

 Pilcomayo and Vermejo flow through this country, which at present 

 belongs neither to Bolivia, to Paraguay, to Brazil nor to the Argen- 

 tine Republic. Different Indian tribes are still the possessors of this 

 large territory. To study these Indian tribes and make them more 

 useful to the Argentine Republic, Mr. Porter Cornelius Bliss, a 

 North American citizen, was sent to that country, by the govern- 

 ment, in the month of February, 1863. After his return to Buenos 

 Ayres he reported to the national government the results of his 

 investigations. In this valuable report, Mr. Bliss stated that the 

 ground of the Gran Chaco is covered in several places with large 

 masses of meteoric-iron. This metedric-iron contains 10 per cent. 

 of nickel; that of Macama in Bolivia contains only 2 1-2 per cent, 

 of nickel. To make the statement of Mr. Bliss more complete, I 

 will add that a large mass of meteoric-iron, of nearly 30,000 pounds 

 weight, was found, at the end of the last century, at Otumpa, in 

 latitude 27° or 28°, about seventy leagues eastward from Santiago. 

 Mr. Parish, the well-known English traveller, sent, during his stay 

 in this Republic, a large piece to London, where it is preserved in 



