440 
WISCONSIN STATE AGRICULTURAL SOCIETY. 
and extend with the strata to a depth as yet unknown; it is stated that the 
metalliferous strata are’at times more than 45 fathoms thick. The sand¬ 
stone is filled throughout its wdiole mass with grains of galena, (varying in 
size from a pin head to that of an apple, the coarser grains being most rare,) 
which are distributed with most surprising regularity. Larger grains are 
extremely rare; more commonly they decrease in size so as to be barely 
visible. The interior of these grains nearly always contains fine sand ce¬ 
mented together by galena; from which it appears to me clear that the grains 
are not found in secondary deposits, which liko a kind of alluvial deposit, 
have been only accidentally washed together w T ith the sand; but that the 
ore was either forme.d contemporaneously with the sandstone, or penetrated 
it subsequently by a process of impregnation.” 
C. Haber,” says the same writer, “ has very recently described this lead 
ore deposit. He explains its formation by impregnations, which have pen¬ 
etrated from numerous fissures traversing the sandstone. These fissures 
appear to be connected with true veins of galena, occurring in the Devon¬ 
ian strata beneath the sandstone.” 
The writers above quoted are not only good authority, but 
perhaps our best authority on all questions relating to min¬ 
eral veins and ore-deposits, and their opinions should be 
received with a great deal of confidence. If we adopt as a 
theory their views as expressed above in reference to the 
origin of that ore deposit in the sandstone, namely, that it 
extended by a process of impregnation through fissures receiv¬ 
ing their material from older formations below, we shall find 
that it will explain very readily certain phenomena found in 
connection with a certain class of ore-deposits sometimes found 
in sandstone and limestone that have been but lightly dis¬ 
turbed. 
If thermal water rising through fissures in older rocks below 
should penetrate a bed of loose quartzose sandstone resting 
upon them, nothing would be more reasonable than to sup¬ 
pose, that such water, holding mineral matter in solution— 
whether dissolved out of original veins below or obtained from 
sublimations at greater depths—would impregnate the sand¬ 
stone along the line of those original fissures. And inasmuch 
as we find quartz and iron, quartz and galena, quartz and cop¬ 
per, and even quartz and gold in the same vein, there is no 
scientific reason why they may not—in the absence of proper 
conditions for forming veins—be associated in this way. 
