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quently found loose on the surface. Some fossils of the asbestos 

 kind and some very poor oxides of iron are likewise to be met with 

 occasionally. The bases of many of the conical granite mountains 

 are overlaid with (apparently) primitive lime-stone of an obscure blue 

 colour, in laminae ; I found in this substance many capillary veins of 

 calx-^ar, and sometimes crystals of pyrites. In one part of the 

 vicinity there is a plain about half a mile square, on the surface of 

 which are found large quantities of white lime-stone in nodules ; it 

 is of a very close texture, but being considered inferior in quality to 

 the other species it is never converted into lime. The summits of 

 these mountains are no where calcareous, excepting those of one 

 ridge, the singular appearance of which induced me to trace it as 

 far as was practicable. The lime-stone on these summits is of a 

 close compact kind, united to transparent quartz in a tabular form, 

 standing, as it were, in laminae perpendicular to the horizon, and 

 thus presenting to the view a number of upright slabs somewhat 

 similar to the grave-stones in a country church-yard. This singular 

 ridge apparently commences at a mountain of very unusual form, 

 and, extending about two miles, in which it crosses two or three 

 valleys, terminates in a ravine of considerable depth. No vestige 

 of calcareous crystallization appeared in this lime-stone*. It is 

 singular to remark, that the cavities formed by the laminae afford 

 refuge for reptiles, particularly rattle-snakes ; the person employed 

 by Mr. Martinez in getting the stone destroyed upwards of twenty- 

 seven serpents of that species in the course of a few weeks. 



The lime-stone is loosened by the wedge and lever, and brought 

 away in large slabs to the kilns, where it is broken into fragments of 

 a convenient size, and burnt with wood. The kilns are capacious, 

 but so badly constructed that the process of calcination is very 



* At a small town called Minas, ten leagues from Maldonado, I was informed that there 

 was a lead mine in lime-Stone. A piece of that substance was sent to me j it was flesh- 

 coloured, granular, and close in texture. 



