•204 
MOUNTAINS 
OF 
COLUMNAR PORPHYRY 
OF JACAL. 
PLATE LXV. 
This view was taken from the plain of Copal- 
linchiche^ which forms a part of the great Mexi- 
can plain, and is thirteen hundred toises (2530 
metres) above the level of the ocean. The 
mountains of Oyamel and Jacal, composed of 
enormous columns of trappean porphyry, are 
crowned with pines and oaks. It is between 
the farm of Zeinbo and the Indian village of 
Omitlan, that the celebrated mines of iztli, or 
obsidian, worked by the ancient Mexicans, are 
found. This spot is called in the country, the 
mountain of knives^ el Cerro de las Nahajas, The 
summit of Jacal is sixteen hundred and three 
toises (3124 metres) in height. My sketch gives 
the outlines of the Cerro de Santo Domingo (1), 
of Mocaxetillo (2), of Orcones (3), and of Jacal, 
or Cerro Gordo (4). 
