well ...

there was nothing more to it than polymax single weight fiber paper that is long expired ..
a box camera and the sun. i can't speak about gases being emitted and silver cations ...
all i can say is that there is something interesting about just plain old photo paper and
how it can be exposed for a short burst of light and yield a beautiful image, or
a long period of time, and yield an image ..

maybe the secret is there is no secret at all it is just a long exposure
that monsieur bayard did, and everyone just figures that it was a short exposure because,
many other emulsions were short exposures ....