stone), which
eventually led him to the discovery of lithography had been used by
him as a slab upon which he had been accustomed to grind his printing
ink. The materials which he used for his acid-resisting mixture while
etching his copper plates were beeswax, soap, and lampblack, and in
selecting these materials he accidentally invented the basis for all
crayons or lithographic "tusche" or inks, now used so extensively for
drawing on stone. It seems that Senefelder finally became thoroughly
disheartened about his etched copper plates, mainly owing to the great
expense and labor connected with their production, and was about to
discontinue his efforts when the idea occurred to him to experiment
with the stone which he had used as an ink slab for so many months,
treating it in the same manner as the copper plates.

He knew that the calcareous stone was easily affected by acid and that
he could protect its surface against it by a layer of wax. After
polishing the surface of the stone and coating it with a slight layer
of wax, he made his drawing with a pointed tool, laying bare the
surface of the stone where he desired the engraving. Then applying the
acid and removing the remaining wax, he filled the etched lines with
printing ink, cleaned the surface of the stone with water, and was
enabled to obtain an impression on paper from it. This manner of
treating a stone has been employed by vignette engravers for many
years, but of late has become obsolete. The result gave encouragement
to Senefelder and induced him to renew his experiments, when he was
accidentally led a step farther in the direction of surface or
chemical printing.

Senefelder had just ground and polished a stone, when his mother
entered the room and asked him to take a memorandum of some clothes
which she was about to send away to be laundered. Having neither paper
nor ink at hand, he hastily wrote the items with a pen, dipped in his
acid-resisting mixture, upon the stone which had just been polished.
When he afterwards started to wipe the writing from the stone, it
occurred to him that it might be possible to reverse his process by
etching the surface of the stone, leaving the writing or drawing in
relief, which could be printed from in the same manner as from type.
He was fairly successful in this, and after many disappointments and
much hardship, he eventually succeeded in interesting a capitalist,
with whose assistance he was enabled to establish hi