[CHAPTER V.]
NEGATIVE PROCESS—SOLUBLE COTTON—PLAIN COLLODION—DEVELOPING SOLUTION—RE-DEVELOPING SOLUTION—FIXING THE IMAGE—FINISHING THE IMAGE—NITRATE OF SILVER BATH.
Negative Process.
The manipulations and chemicals employed in the production of the negative collodion pictures are very similar to those already given for operating by the positive process; frequent reference will therefore necessarily be made to portions of that process, as described in the preceding pages, and only such parts will be given here, as do not correspond with the foregoing.
It is thought advisable to omit in this chapter every reference that does not have a desired tendency to aid the operator in the plain straightforward order of manipulation. The negative process is fast becoming popular and needs the attention of all who desire to keep pace with the experiments in the art. Since the first edition of this work it has been my pleasure to see many fine photographic specimens produced by the following process, and no one need fail, if he will carefully adhere to the details given.
There perhaps may be circumstances making it advisable for some to have but one nitrate of silver solution for both positive and negative collodion pictures: for such, a process will be given in the following pages, which has recently appeared in Humphrey's Journal, and is called, after its author, the "Helio Process," this is well adapted for most purposes.
Soluble Cotton.
The method for preparing this has been given in page 41. It is prepared in the same manner for both positives and negatives.
Plain Collodion.