s new relief stone
process on a commercial basis.

The process, however, was at best only an imperfect one, and it seems
strange that the final discovery of surface or lithographic printing
should have been so long delayed, when Senefelder was in reality so
near it, when he first poured the acid over the stone containing his
laundry memorandum. If he had instantly washed off the acid and
cleaned the surface of the stone with water, he might have proceeded
to print thousands of impressions by simply keeping the surface of the
stone moist while passing the ink roller or dabber over it, then
drying and taking an impression, and repeating this operation
indefinitely. It is not surprising, therefore, that a man of such
persistence and capability as Senefelder should eventually discover
the best method for drawing and printing from stone; for it is a fact
that, since he perfected his invention, more than a hundred years ago,
it has been hardly possible to improve on his methods, so completely
did he cover the entire field of manipulation in this direction.
Continuing his experiments, Senefelder finally found that the
calcareous stone absorbed and held grease, and that it just as readily
absorbed water, where the surface was exposed and clean; that any
design drawn or transferred with a greasy crayon or ink upon a cleanly
polished stone would be firmly held, after being slightly etched; and
that after such a stone had been moistened, it could be inked with
rollers, the ink adhering only to the greasy matter constituting the
design (although it did not stand out in the relief) and that the ink
rollers would not smut the stone, the ink being repelled by the water
or moisture covering its surface. Upon this principle of chemical
affinity, the adherence of greasy substances to each other and the
mutual antipathy of grease and water, the art of lithographic printing
is based.

The methods or processes now employed in reproducing oil-paintings,
colored photographs, or water-colors by lithography are numerous, and
require great skill and experience, not only on the part of the
lithographic artist, but also on the part of the printer. Photography
has of late years been used to a great extent in creating the basis of
the color plates, to be afterwards perfected by the manipulation of
the experienced chromo-lithographer.

To insure a satisfactory result the first essential is, of course, a
good original, which can be made in water-c