Dan,
I haven't tried anthotypes but here is a little information which i hope will
be helpful.
I'm just back from England (its the 9th or 10th of July today, but my watch has
gone completely haywire, ie crazy) & etc, and part of my reseraches there have
lead me right past the above mentioned flower juice prints of Herschel. I
actually got to see a flower print, in-the-flesh, so to speak. It, or they,
exist! The bad news is Dan, that according to source in Oxford, exposures did
take Herschel in the vicinty of a week. The image is *faint* (compared to what
everybody compares photographs to for some reason beyond me - which is a
commercially produced silver gelatin paper) but an image is definitely there.
The good news is that they probably don't fade! It is assumed that the prints
look today just like they did. Others may have a different opinion on that. I'm
not an expert, but am extremely interested in Herschel's photographic
processes, and a willing speculator on the subject:-)
Now, you can actually find out what flowers Herschel used by reading the 1842
edition of what is usually referred to as the Phil. Trans. (that is, the
abstracts of papers presented to the Royal Society, published as the
Philosophical Transactions of the Royal Society etc; a good university library
should carry copies). Herschel lists the flowers he used in an 1842 paper. A
red poppy now flowering profusely in England, is one which Herschel
successfully obtained a print with.
Herschel, who had difficult to read writing, wrote on the back of most of his
prints, stating flower, chemistry etc. There are seperate notes on all these
experiments somewhere, but I am not the person to ask. I gather that these
notes have not been catalogued however. There is a worthwhile job for a
committed archivist. But you may find sufficient technical information for your
needs from Herschel's own accounts which are quite detailed if i remember
correctly.
As I said, i know there are people whose knowledge is far more extensive than
mine, but i can verify that such prints exist.
Please, if you give this a go, I'd love to be kept informed about your results.
Maybe i can dig up more, info, i'm still jet lagged at the moment.
Best of luck
and cheers
Catherine