| Hyposulphite of soda | 1 ounce. |
| Water. | 8 |
The fixing will require from five to ten minutes; then wash and pass the prints through a clearing solution consisting of
| Alum | 2 ounces. |
| Water | 6 |
then wash again and hang up, or place between clean blotters to dry.
It is necessary that the hands be free from any trace of silver or hypo when handling these prints while developing, or afterwards when wet, to avoid stains, etc. The same precautions as to the relative proportions of the oxalate solution and the iron are to be observed as for the development of negatives. p197
THE MAGIC LANTERN AND ITS USE
The Magic, or, more properly, the Projecting lantern, is an optical instrument, consisting of a case of wood or metal, enclosing a lamp or other illuminating agent, the light of which being gathered and condensed by a suitable condensing lens, and directed upon a small transparent picture, so powerfully illuminates it that its image, brilliantly lighted and greatly magnified, may be projected upon a distant screen by means of an objective—a combination of lenses in a tube—similar or identical in construction with a photographic portrait lens.
The modern projecting lantern, now a scientific instrument, bears very little if any resemblance to the earlier magic lantern, which was a rude construction, and, as its name implies, was first used by magicians, or professors of the magic arts, as a means of imposing upon the ignorance and superstition of their times. Later it became a toy for the amusement of young people. And occasionally it furnished amusement for popular assemblies, at what were called Magic lantern exhibitions, usually the projection upon a screen of greatly enlarged images of a series of comic pictures painted in brilliant colors upon glass.
The perfected instrument is now used in advanced schools and colleges for illustrating scientific lectures, and more popularly by public lecturers to illustrate by luminous projection scenes and incidents of travel, etc., without which the mere narrative would be exceedingly dry and devoid of interest.
Since dry plate photography became a popular amusement, the projecting lantern has greatly increased in public favor, and the members of the amateur p198 photographic societies and camera clubs throughout the country are interested and engaged in the production, as slides for the lantern, of views of almost everything in animate or inanimate life.