rant odour similar to a fresh lemon, and does not abrade the surface.
The fictitious amber, on the contrary, breaks or becomes rough, and has a
resinous turpentine-like smell. Genuine amber is to be obtained generally
of the tobacconists, who have often broken mouth-pieces by them: old
necklaces, now out of use, are sold at a very moderate price by the
jewellers. The amber of commerce, used in varnish-making, contains so much
impurity that the waste of chloroform renders it very undesirable to use.
The amber should be pounded in a mortar, and, to an ounce by_ measure _of
chloroform, add a drachm and a half of amber (only about one-fourth of it
will be dissolved), and this requires two days' maceration. It should be
filtered through fine blotting-paper. Being so very fluid, it runs most
freely over the collodion, and, when well prepared and applied, renders the
surface so hard, and so much like the glass, that it is difficult to know
on which side of the glass the positive really is. The varnish is to be
obtained properly made at from_ 2s. _to_ 2s. 6d. _per ounce; and although
this appears dear, it is not so in use, so very small a portion being
requisite to effectually cover a picture; and the effects exceed every
other application with which we are acquainted,--to say nothing of its_
instantaneously _becoming hard, in itself a most desirable requisite._

---- (Islington). _Your note has been mislaid, but in all probability the
spots in your collodion would be removed by dipping into the bottle a small
piece of iodide of potassium. Collodion made exactly as described by_ DR.
DIAMOND _in_ "N. & Q.," _entirely answers our expectations, and we prefer
it, for our own use, to any we have ever been able to procure._

J. M. S. (Manchester) _shall receive a private communication upon his
Photographic troubles. We must, however, refer him to our advertising
columns for pure chemicals. Ether ought not to exceed_ 5s. 6d. _the pint of
twenty ounces._

_A few complete sets of_ "NOTES AND QUERIES," Vols. i. _to_ vi., _price
Three Guineas, may now be had; for which early application is desirable._

"NOTES AND QUERIES" _is published at noon on Friday, so that the Country
Booksellers may receive Copies in that night's parcels, and deliver them to
their Subscribers on the Saturday._

* * * * *

This day is published,

PICTORIAL ILLUSTRATIONS of the Catalogue of Manuscripts in Gonville and
Caius Coll