ensitiveness of the prepared
collodion plate depends rather upon the strength of the nitrate of silver
bath than on the collodion, I am desirous of asking how far the experience
of your correspondents confirms this statement. My informant assured me,
that if, instead of using a solution of thirty grains of nitrate of silver
to the ounce of water for the bath, which is the proportion recommended by
Messrs. Archer, Horne, Delamotte, Diamond, &c., a sixty grain solution be
substituted, the formation of the image would be the work of the fraction
of a second. This seems to me so important as to deserve being brought
under the notice of photographers--especially at this busy season--without
a moment's delay; and I therefore record the statement at once, as, from
circumstances with which I need not encumber your pages, I shall not have
an opportunity of trying any experiment upon the point for a week or two.

Upon referring to the authorities on the subject of the best solution for
baths, I have been struck with their uniformity. One exception only has
presented itself, which is in a valuable paper by Mr. Thomas in the 6th
Number of the _Journal of the Photographic Society_. That gentleman directs
the bath to be prepared in the following manner:

Into a 20 oz. stoppered bottle, put--

Nitrate of silver 1 oz.
Distilled water 10 oz.
Dissolve.

Iodide of potassium 5 grs.
Distilled water 1 dr.
Dissolve.

On mixing these two solutions, a precipitate of iodide of silver is formed.
Place the bottle containing this mixture in a saucepan of hot water, keep
it on the hob for about twelve hours, shake it occasionally, now and then
removing the stopper. The bath is now perfectly saturated with iodide of
silver; when cold, filter through white filtering paper, and add--

Alcohol 2 drs.
Sulphuric ether 1 dr.

The prepared glass is to remain in the bath about eight or ten minutes.
Now, is this bath applicable to all collodion, or only to that prepared by
Mr. Thomas; and if the former, what is the rationale of its beneficial
action?

A BEGINNER.

* * * * *

Replies to Minor Queries.

_Mitigation of Capital Punishment to a Forger_ (Vol. vii., p. 573.).--If
your correspondent H. B. C. really wishes to be released from his hard work
in hunting up the truth of my and other narratives of the _mitigation of
capital punishment to forg