A Manual of the Collodion Photographic Process - The Collodion Process


Contents

Part 1

Part 2

PART III


The Collodion Process

Although it is not my intention to enter into any detailed account of the chemical preparations used in this photographic process, still I am anxious to offer a few remarks with reference to the manner in which I consider the collodion solution can be best prepared, of suitable strength and firmness; for these two qualities must be considered indispensable, especially when large surfaces of glass are to be covered. When working with small quantities these two qualities may not be considered so important as they really are; and further, when the pictures are to be rolled up, or whitened with the bi-chloride of mercury solution, the strength of the collodion is of essential importance.

My object is to promote the use of a strong and firm film, which will bear removal from the glass when this operation is considered necessary; and will equally well dry on the glass when the drawing is finished. I should first wish to point out the mode of preparing the gun cotton, and afterwards proceed to describe the collodion solution.


There are two receipts for making gun cotton, from either of which a good dissolving cotton may be obtained.


Several others have been described, but I should only be confusing the subject to attempt to give the whole; and it would be foreign to the limited purpose of this work to do so.


The results, however, vary so much with the strength and proportion of the acids used, as to render it extremely difficult to name any one in particular, which would entirely succeed under all circumstances. In all cases it is more easy to prepare a cotton which will explode readily, and yet not be at all soluble, than
one which will entirely dissolve in rectified sulphuric ether.

Few will be able to avail themselves of these receipts, unless they previously possess sufficient knowledge of chemistry to ensure a tolerable hope of success, for it requires considerable practice and very many trials before a good cotton can be prepared.

I give them for the use of those, who are by circumstances placed in such a position, as to entail upon them the necessity of preparing it themselves, when the consideration of cost cannot be taken into account.