"The above gives the bright deposit of silver so much admired in Dr. Diamond's pictures, and will be found to answer equally well either for positives or negatives. If the nitric acid be omitted, we obtain the effects of protonitrate of iron prepared in the usual way.--JOHN SPILLER." (From the _Photographic Journal_.) _Photographs in natural Colours_.--As "N. & Q." numbers among its correspondents many residents in the United States, I hope you will permit me to inquire through its columns whether there is really any foundation for the very startling announcement, in Professor Hunt's _Photography_, of Mr. Hill of New York having "obtained more than fifty pictures from nature in all the beauty of native coloration," or whether the statement is, as I conclude Professor Hunt is inclined to believe, one of those hoaxes in which many of our transatlantic friends take so much delight. MATTER-OF-FACT. _Photographs by artificial Lights_.--May I ask for references to any manuals of photography, or papers in scientific journals, in which are recorded any experiments that have been made with the view of obtaining photographs by means of artificial lights? This is, I have no doubt, a subject of interest to many who, like myself, are busily occupied during the day, and have only their evenings for scientific pursuits: while it is obvious, that if such a process can be successfully practised, there are many objects--such as _prints_, _coins_, _seals_, _objects of natural history and antiquity_--which might well be copied by it, even though artificial light should prove far slower in its action than solar light. A CLERK. * * * * * Replies to Minor Queries. _Vandyke in America_ (Vol. viii., p. 182.).--I would take the liberty of asking MR. BALCH of Philadelphia whom he means by Col. Hill and Col. Byrd, "worthies famous in English history, and whose portraits by Vandyke are now on the James River?" I know of no Col. Hill or Byrd whom Vandyke could possibly have painted. I should also like to know what proof there is that the pictures, whomsoever they represent, are by _Vandyke_. MR. BALCH says that he favours us with this information "_in answer to the query_" (Vol. vii., p. 38.); but I beg leave to observe that it is by no means "in answer to the query," which was about an _engraved_ portrait and not _picture_, and {229} his thus bringing in the Vandykes _a propos de bottes_ makes me a little curious about their authenticity. C. _Title wanted--Choirochorographia_ (Vol. viii., p. 151.).--The full title of the book inquired after is as follows: "[Greek: Choirochorographia]: sive, Hoglandiae Descriptio.--Plaudite _Porcelli Porcorum pigra Propago_ (Eleg. Poet.): Londini, Anno Domini 1709. Pretium 2^d," 8vo.