



191 



should endeavour as early as poatible to make himself 

 .ir wuh the characteristic mineral subnanctt which 



may contain uef part of the veins. Such 



rals as quartz, barytes, calcttc, and other "vein 



stones," as they are called, are of common occurrence, 

 MI local peculiarities by which they may 



be recognised and traced to their sources. Having ex- 



is of some of the mineral veins and learnt 

 the way in which the veinstones are associated with any 

 metalliferous ore, the observer may be on the watch for 

 nee of the occurrence of the veins elsewhere. He 

 follows with this view the same plan as that which I have 

 already described with reference to the tracing of the 

 of formations by means of scattered surface frag- 

 (a*tt, p. 92). In ascending a stream or a hillside, 

 he takes note of any marked number of pieces of vein- 

 stone, and of the point beyond which they grow fewer or 

 cease. Having thus got a rough indication of the existence 

 of one or more veins, he proceeds to a more minute search 



