T. MASSEY (Manchester) _is referred to Richardson's_ Dictionary, _s. v._ with, within, without, _for a solution of his Query_. Nisi Prius _are the first words on certain legal records, where an issue is appointed to be tried by a jury from the county,_ unless before _the day appointed (nisi prius) the judges shall have come to the county in question. The judges of assize, by virtue of their commission of_ nisi prius, _try the causes thus appointed_. E., _who asks the origin of "Mind your P's and Q's," is referred to our_ 3rd Vol., pp. 328. 357. 463. 523. BALLIOLENSIS. _We are flattered by the suggestion of our Correspondent, but we must leave the agitation which he suggests to abler hands._ PHOTOGRAPHIC NOTES. _In consequence of the number of_ REPLIES TO MINOR QUERIES _waiting for insertion, we have been compelled to postpone the_ REV. MR. SISSON_'s description of a new_ Head-rest, _and_ SIR W. NEWTON_'s explanation of his_ Process. A. S. K. (Worthing) _is informed that it is quite useless to extract the size from the paper of positive pictures, to ensure their permanence. If the hyposulphite of soda is entirely freed from them, they will bear any exposure to atmospheric influence without change. Although in all works on Photography it is recommended that the size should be extracted from negatives before waxing them, it is a process we have entirely dispensed with: if the iron is used sufficiently hot, the wax will perfectly permeate the entire texture of the paper. Our Correspondent is referred to our back Numbers for an account of the mode of taking a positive picture on glass from a glass negative._ R. S. C. (Solihull) _shall receive a private communication on the subject of the construction of his glass house for Photographic purposes. There are points in it which are not generally attended to, and upon which the want of success of many operators has no doubt depended._ TYRO (March 14th). _The second sample of collodion which you have used is_ over-_iodized. It is quite requisite that it should be known that the sensitive properties of collodion are not increased by adding too much of the iodizing solution. If the collodion is good, the film is semi-transparent, of a bluish opal-like appearance. If the iodine is in excess, it becomes more opaque and creamy after immersion in the bath, and of a deep orange when looked through; whereas it should appear of a pale amber colour._ TYRO (March 17th). _The reticulated appearance you complain of is from using your collodion too thick, and not giving the glass the rotatory rocking motion which you should do when you drain off the excess into the bottle. Prepare two pieces of glass with collodion: in one simply drain off the excess of collodion, and in the other use the motion which has been before described, and you will perceive the difference in the evenness of the two films._