12 
slate-clay, not applicable to any use, except perhaps to make 
bricks. 
Within a gunshot of the place where the above-mentioned 
agent related this anecdote, the appearance of some rather 
ferruginous slate rock attracted the attention of a party of cre- 
dulous speculators, who believing they had discovered a rich iron 
ore, actually built a blast furnace, erected the necessary machi- 
nery, and continued for some time to carry out their vain attempt, 
deluded by the fraudulent practices of the workmen. As might, 
however, have been predicted, the undertaking soon ended in 
abandonment and ruin. 
In other mining districts I have known persons, who although 
possessed of great general intelligence, have collected blue stones 
(generally ores of copper) for cobalt, ignorant of the fact that 
none of the natural combinations of this valuable metal possess 
a blue colour. 
The sulphate of baryta has for a few years past borne a cer- 
tain value for manufacturing purposes ; and an instance was 
brought to my notice, where a ship-load of what was supposed 
to be this»mineral was obtained by surreptitious means, and sent 
from a distant part of the country to London. But the biter 
was bit, for his observation was faulty, and his cargo, proving to 
be calcareous spar, was worthless. It would tire out your 
patience to enumerate the cases in which mica or iron pyrites 
have been mistaken for gold. From the anxious country gentle- 
man in our own land, to the disappointed Californian gold 
seeker, and to the solemn Turkish Bey mysteriously unwrapping 
from many a folded rag the specimen of his expected wealth, 
such victims of mineralogical ignorance are frequently presented 
to those whose pursuits bring them into a position for advising 
on similar points. 
But there is another and a wider field far more important 
than the correction of isolated mistakes, in which mineralogical 
research has yet to be largely employed, and in which the con- 
nexion of this subject with mining is no less grave than intimate. 
The principles by which the accumulation of ore in lodes or 
metalliferous veins has been regulated are to this day so en- 
veloped in mystery, that the prosecution of mining enterprises is 
almost as much a matter of chance as it was with our forefathers 
