Читать книгу A Practical Manual of the Collodion Process. Giving in Detail a Method For Producing Positive and Negative Pictures on Glass and Paper онлайн

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Plain Collodion.

PLAIN COLLODION.

To dissolve the soluble cotton (pyroxyline), and form plain collodion, proceed as follows:

Take of

Sulphuric ether (concentrated), 10 ounces Alcohol, from 90 to 95 per cent., 6 "

Soluble cotton enough to give the solution a consistency such as will allow it to flow evenly over the surface of the glass, and impart to it quite a thick and transparent coating. If the coating is opaque, the cotton has not been properly prepared, the acid mixture has been too weak.

Remarks.—It is desirable for every operator to use chemicals of uniform strength, and the better method to adopt is to employ those purchased from some one respectable manufactory, and not take those furnished by irresponsible and unconscientious parties. At least one-half of the failures experienced by beginners is from want of good chemicals. It is not economy to purchase a cheap article.

Alcohol is an article that can be procured in almost any small village in the United States, and is in general fit for collodion purposes. I have used 88 per cent, in the above proportions, also the intermediate varieties to 98 per cent., and have been quite successful; but feel convinced that the ordinary 98, as marked (which usually stands by actual test 95 to 97 per cent.), is preferable, except in cases where water is employed in dissolving the iodizing salts, when I would use fully 98 per cent.