S. W. L. _is assured that the communications to which he refers interest as
large and intelligent a class of readers, as will feel an interest in the
communication which he proposes to forward, and which we shall gladly
receive_.
C. D. W. T. (Jun.) _is thanked: but the edition is too well known to all
the Communicators, to require that he should be troubled upon the subject_.
J. H. W._'s communication shall have early insertion. Our arrangements
would not admit of its appearing this week._
TYRO. _The anonymous_ Life of Queen Anne _inquired after_ (Vol. vii., p.
108.) _is a different work to that of Boyer's, and does not contain
one-third the quantity of letter-press. The descriptive matter of the_
Metallick History _has been copied from Boyer, although the plates have
been re-engraved_.
MR. BROWN'S _Letter on_ MR. ARCHER'S _Services to Photography_; G. H. _on
Difficulties in the Wax-Paper Process; and_ F. M. L. _on the Albumen
Process, are unavoidably postponed until next week_.
A. B. _Your suggestions will be attended to in the_ NOTES ON PHOTOGRAPHY.
ENQUIRER (Edinburgh). _If you follow the instructions given in our former
Numbers on the Collodion Process, you must meet with success. The deposit
in negatives is often much blackened by adding an increased proportion of
acetic acid to the pyrogallic solution--say two drachms to the ounce, so
that the solution shall be one-fifth of acetic acid. A_ long _exposure
often weakens a negative; and, during the recent fall of snow, thirty
seconds has produced an effective printing negative, whilst three minutes'
exposure has given a negative picture so transparent as to be useless_.
E. F. (Sheffield). _It is only in converting a positive picture into a
negative one, or in increasing the powers of a feeble negative, that the
bichloride of mercury is recommended to be used. A perfectly good printing
negative will be procured by following the instructions we have given in
our former Numbers._ DR. DIAMONDS'S Photographic Notes _will treat fully
upon this subject_.
OUR SIXTH VOLUME, _strongly bound in cloth, with very copious Index is now
ready, price 10s. 6d. Arrangements are making for the publication of
complete sets of_ "NOTES AND QUERIES," _price Three Guineas for the Six
Volumes_.
"NOTES AND QUERIES" _is published at noon on Friday, so that the Country
Booksellers may receive Copies in that night's parcel, and deliver them to
their Subscribers on the Saturday_.
* * * * *
{195}
PHOTOGRAPHY.--Collodion (Iodized with the Ammonio-Iodide of Silver).--J. B.
HOCKIN & CO., Chemists, 289. Strand, were the first in England who
published the application of this agent (see _Athenæum_, Aug. 14th). Their
Collodion (price 9d. per oz.) retains its extraordinary sensitiveness,
tenacity, and colour unimpaired for months: it may be exported to any
climate, and the Iodizing Compound mixed as required. J.B. HOCKIN & CO.
manufacture PURE CHEMICALS and all APPARATUS with the latest Improvements
adapted for all the Photographic and Daguerreotype processes. Cameras for
Developing in the open Country. GLASS BATHS adapted to any Camera. Lenses
from the best Makers. Waxed and Iodized Papers, &c.
* * * * *
TO PHOTOGRAPHERS.--Pure Chemicals, with every requisite for the practice of
Photography, according to the instructions of Hunt, Le Gray, Brébisson, &c.
&c., may be obtained of WILLIAM BOLTON, Manufacturer of pure chemicals for
Photographic and other purposes.
Lists of Prices to be had on application.