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MODERN DEVELOPERS gave results precisely similar in practical use. It was said to be of geniune Swiss manufacture, probably from a German-made intermediate. This developer was introduced by moa the Eastman Kodak Company some time ago, for use with hydroquinone in a combination said to exactly duplicate the well-known M-Q or Eastman Metol-Quinol developer. Elon is not at present on the market, but the combir.ation referred to, advertised as Tozol, is still obtainable. These two pre-war developers, said Sa~ofJ1: to be identical with metol, fhe first made by Schering and the second by Mallinckrodt, are no longer obtainable. Very interesting, but difficult to lloaomet place, is the British product Monomet, introduced early in 1916 and controlled iii America by the Ansco Company. On the other side it is widely used as a universal developer for plates, films, lantern slides, bromide and development papers. In this country it seems to be used chiefly in combination with hydroquinone as a developer for development papers such as Cyko. In practical use for two years it has proved an altogether satisfactory and efficient substitute for German metol. Of the chemical composition of What Is It? Monomet its makers tell us nothing more than that it is a derivative of cresol-as was the first German metol according to Hauff; and in concentrated solutions with sulphite and alkaline carbonate it throws down a precipitate of amido-cresol base. Its makers advertise it as a "British form of metol" having the following characteristics: (r) "Monomet will go very much further, in regard to the number of prints it will develop, than metol. (2) Monomet is not quite as soluble, in combination with sodium sulphite, as metol," upon which they base the claim that it is 25 per cent purer (as a chemical product) than German metol. According to the report of the Ansco Research Laboratory, based upon exhaustive analysis and comparisons, it is not identical with German metol, "for

Modern Photographic Developers  

A Practical Handbook to the New Developers Telling What They Are and How to Use Them with Reliable Formulae by The Photo Miniature, January...