Maidstone.
_Yellow Bottles for Photographic Chemicals._--The proposal of your
correspondent CERIDWEN to employ yellow glass bottles for preventing the
decomposition of photographic solutions has been anticipated. It was
suggested by me, in some lectures on Photography in November 1847, and in
January of the present year, that yellow bottles might be so used, as well
as for preventing the decomposition, by light, of the vegetable substances
used in pharmacy, such as digitalis, ipecacuanha, cinchona, &c. For
solutions of silver, however, the most effectual remedy against
precipitation is the use of very pure water, procured by slow
redistillation in glass vessels at a temperature much below the boiling
point.