Quote Originally Posted by Photo Engineer
Added to the halides you mention there are Fluorine and Astatine. Now, these are not used, but why not would iin itself cover a chapter in a book...
From here, http://www.apug.org/forums/viewpost.php?p=1103794

Interesting question. Regarding water-solubility, consider Daguerreotypes. Water doesn't even figure in to these; so maybe there's some way??