96 KANSAS CITY REVIEW OF SCIENCE. 
The whole of the rich agricultural region of the Mississippi; the whole of the 
Western plains, through all their extent to the one hundred and second meridian 
west from Greenwich, and on their northern section to the one hundred and tenth 
meridian ; the whole of the low-lying plains of the Southern States, in all con- 
taining a little over one half the total area of the United States, but at least nine 
tenths of its arable land, is sure never to prove productive of any the metals 
now known to the arts, save iron, lead, and aluminium; and of these lead will 
never be again economically produced there, until the mining industry of the 
Cordilleran region begins to wane. 
This rejection of the larger part of national area from the list of regions 
where gold and silver may be found in profitable quantities is based upon actual 
experience of the generations grown up within the area, as well as the general 
fact that the experience of other countries shows us that such rocks as underlie 
this region are always marked by the absence of gold and silver in profitable 
quantities. 
Of late years there has been a great advance toward a learc understanding 
of the natural processes by which metallic deposits are brought into the shape in 
which the miner findsthem. Allthe old notions about the outburst of mineral veins, 
by fiery ejection from the deep interior of the earth, have been cast aside. Geol- 
ogists now pretty generally recognize the fact that all our metals are deposited in 
our stratified rocks as they are laid down on the sea-floor, having been sepa- 
rated from the sea-water, as a great part of all the rocks are, by the action of 
sea-weeds and marine animals. - eos “s a *k oS 
Whoever looks over the whole field of American precious metal mining will 
be convinced that this industry is certain to make a very rapid growth in what is 
left of this century.- He will also come to the conclusion that the production of 
silver is destined to increase very rapidly for a score or so of years to come, pro- 
vided the demand for this much slandered metal does not fall too far short of the 
supply. Beyond a brief term this yield of silver will surely diminish, especially 
if there is any considerable lowering in its price. ‘The observant eye can also 
see that the production of gold is likely to extend to many new fields, and that 
the yield of this metal is in the future likely to be rather more steady than that 
of its bulkier sharer in the greed of men. North America and the twin con- 
tinent on the south are doubtless to be the great producers of precious metals in 
the future; their store of silver must be of greater value at the present price of 
this metal than their store of gold. If the world continues to use silver in the 
coming century as it has in the past thirty centuries, there is a fair prospect that 
our continent will win some thousands of millions from its silver-bearing lodes. 
Even if we make what seems to me the mistake of using gold alone as a basis of 
exchange, the production of this metal will no doubt give us a larger mining in- 
dustry than any other country can expect to gain.—/une Atlantic. 
