Origin op Ironstones. 
123 
Dr. Sterry Hunt, who explains these reactions, 
points out that, as the decomposition of vegetable 
matter is required for the deposition of ironstone, then 
every bed of ironstone is as perfect a record of 
vegetable growth as is a bed of coal. “ We find,” he 
continues, “in the rock formation of every different 
age beds of sediments which have been deprived of 
iron by organic agencies, and near them will generally 
be found the accumulated iron. Go into any coal 
region, and you will see evidences that this process 
was at work when the coal- beds were forming. The 
soil in which the coal-plants grew has been deprived 
of its iron, and, when burned, turns white, as do most 
of the slaty beds from the coal-rocks. It is this 
ancient soil which constitutes the so-called fire-clays, 
prized for making bricks, which, from the absence of 
both iron and alkalies, are very infusible. Interstrati- 
fled with these, we often find, in the form of ironstone, 
the separated metal ; and thus from the same series 
of rocks may be obtained the fuel, the ore, and the 
fire-clay.” 
From what I have said, it will be understood that 
great deposits of iron ore generally occur in the shape 
of beds, although waters holding the compounds of 
iron in solution have in some cases deposited them in 
fissures or openings in the rock, thus forming true 
veins of ore. I wish now to insist upon the property 
which dead and decaying organic matters possess of 
reducing to protoxide, and rendering soluble the 
insoluble peroxide of iron diffused through rocks ; and 
