A/7A/7/ 



"••//, 



ANNALS 



OF THE 



NEW YORK ACADEMY OF SCIENCES, 



VOLUME III. 



I. — The Patio and Cazo Process of Amalgamating Silver Ores. 



BY THOMAS EGLESTON. 



Read, October 1st, 1883. 



The process of amalgamation which is still used both in 

 Mexico and Chili, is called the American method of amal- 

 gamation, in order to distinguish it from the process used 

 so long at Freiberg, known as the Freiberg Barrel Amalgama- 

 tion, and that which has now for so man}- years been almost 

 exclusively used in the western part of this country, known 

 as Pan Amalgamation. It is effected in two different ways, ac- 

 cording to the country in which it is used. In Mexico it is 

 called the Mexican or Patio method, and in Chili it is known 

 as the Chilian or Cazo method. These processes do not differ 

 essentially, except in the mechanical appliances which are used 

 for carrying them on. The Patio method was, until questioned 

 by Dr. Percy,* supposed to have been invented in Mexico, 

 about 1557, for beneficiatiug the silver ores which occur there. 



2-6 



Percys Silver and Gold, Part I, p. 562, London, 1880. 



