"Here is five dollars: send me Humphrey's Journal to this amount. I will not be without it." M. S. "It is my best friend." J. E. W. We might quote like commendatory extracts enough to more than ten times fill this page. Humphrey's Journal contains 16 octavo pages of reading matter. TERMS. One copy per annum, in advance $2 00 Three copies, do. do. 5 00 Six copies, do. do. 9 00 The thousands who read it cannot be induced to remain without it. All who desire to keep up with the improvements should subscribe for a copy. Subscription price Two Dollars per year. Don't fail to become a subscriber. Address =S. D, HUMPHREY,= NEW YORK. [_Office, 37 Lispenard Street_] A PRACTICAL MANUAL OF THE COLLODION PROCESS, GIVING IN DETAIL A METHOD FOR PRODUCING POSITIVE AND NEGATIVE =Pictures on Glass and Paper.= AMBROTYPES. PRINTING PROCESS. ALSO, PATENTS FOR THE COLLODION PROCESSES; MELAINOTYPES--PHOTOGRAPHS IN OIL--ALBUMENIZED COLLODION--CUTTING'S PATENTS AND CORRESPONDENCE.--SPECIFICATION'S OF ALL THE FOREGOING, GIVING EACH PROCESS ENTIRE. THIRD EDITION, REVISED AND GREATLY ENLARGED. By S. D. HUMPHREY. NEW YORK: HUMPHREY'S JOURNAL PRINT, 37 LISPENARD STREET. 1857. Entered according to Act of Congress, in the year 1857, by S. D. HUMPHREY, In the Clerk's Office of the District Court of the United States for the Southern District of New York. PREFACE TO THE THIRD EDITION. ~~~~~~~~~~ The rapid and unexpected sale of the entire second edition of this Manual has induced the author to lay the Third Edition before the Public. Although but little time has elapsed since the second, yet there have been some new developments which it has been thought best to give, as conducive to the interests of the practitioner. The manipulations have been given somewhat more in detail than in the Second Edition. All that would have a tendency to confuse the reader has been carefully avoided, and only the plain methods for operating laid down. The work is intended for the beginner in the glass process of producing Heliographic pictures. S. D. H. New York, _February 1st, 1857_. PREFACE TO THE FIRST EDITION. ~~~~~~~~~~