Porcelain And Opal Transparencies may be developed in the same manner until detail may be seen in the face, if it is a portrait; then remove it and instantly flow with a solution of bromide of ammonium to stop developing action, then wash, fix and dry as before.

For portraits on porcelain or opal, to be viewed as positives by reflected light, develop until the fine halftones in the face are visible. When they are for transparencies, either for window or lamp shades, develop until the detail in the high lights of portrait or landscape are well out. This may necessitate a longer exposure by lamp-light.

Transparencies developed by other methods receive a stain or color, which, in many cases, is not unpleas-ing; for instance, the following formula will give a very beautiful yellowish color:

Saturated solution yellow prussiate of potash,

4 ounces. Pyro.........................2 grains.

Ammonia (cone.)..............2 drops.

This will cover and develop one 8x10 plate, giving it an agreeable color similar to that produced by development by sal soda and pyro, but much more agreeable.

A very fine blue color is imparted to the plate when developed by the following formula:

Saturated solution sal soda.".....5 minims.

Saturated solution potash.......5 "

Saturated solution ferrocyanide of potash......................5 "

Bromide ammonium...........1 grain.

Pyro.........................2 grains.

Water.........................4 ounces.

From the fact that these different developments impart different colors to the negatives, it might be inferred that the gelatine film is susceptible of receiving color from a stain or dye; if such is the case, transparencies may be made in every color of the chromatic or solar spectrum. I have seen one of a beautiful rose color, and was informed that the color was received in development. This was possibly so, but it is very easily ascertained if the film of the developed plate is capable of receiving a dye of any pleasing color suitable to the subject.