"The Chemical Action of Light and the Pea-Sausage.
In the campaign of 1870, the well-known pea-sausage (Erbswurst) was one of
the most important articles of food for the army, and was prepared daily by
thousands. The fabrication of the interior portion caused little
difficulty, but obtaining so many skins created much difficulty. As the
supply fell short, a substitute was sought in vegetable parchment. This
paper, which is produced by dipping blotting paper in sulphuric acid for
about a second, then washing and drying, is distinguished by its skin-like
properties of resistance. It is impenetrable to water, and difficult to
tear. It is therefore used for the production of banknotes. It was
attempted to make sausage skins of this paper by doubling a sheet
cylindrically and pasting it together. No glue or gum can however resist
the effect of the boiling water in which the sausage has to be cooked, and
so the artificial sausage skin fell asunder. Dr. Jacobson solved the
problem by producing an adhesive substance, with the help of the chemical
action of light, which could resist boiling water. He mixed the glue
intended for the sausage skin with bichromate of potash, and exposed the
glued parts to the light. This made the glue insoluble, and now the
artificial skin endured boiling water thoroughly well. The number of
sausage skins prepared in this way, by the chemical action of light,
amounted to many hundred thousands."
Perhaps there is a historian in the Group who can tell us how
successful was the army's campaign of 1870. And who will be the first among
us to make photographically illustrated sausages? The Phagotype : it's
better to eat your pictures than eat your words.
BTW, the Material Safety Data Sheets (from BYU) can be consulted
for toxicological chapter and verse at the following site (which I obtained
from Walter Henry's CoOL resource):
gopher://atlas.chem.utah.edu:70/11/MSDS
Potassium dichromate is categorised there as an 'extreme hazard to health
(cancer causing)'.
Happy printing
Mike