FILMS OF GOLD

Evening Post, Volume CXXIV, Issue 75, 25 September 1937, Page 11

FILMS OF GOLD

BEAUTIFUL MIRRORS

(From "The Post's" Representative.) LONDON, September 4.

Examples of what is described as a new and easy method of depositing films of pure gold .on glass and other surfaces ' have.' been, lent by the discoverer of the, .process, . Professor Charles S. Gibson, of Guy's Hospital Medical. School, to the Imperial Institute. •

According to Professor Gibson, the new method of deposition may have considerable scientific application. A point. of interest aroused in other minds, after inspecting the exhibits, is whether the optilent age of tlie golden mirror has arrived for certain purposes. The films deposited are so extremely thin—the thickest is only 0.004 mm, that, they are transparent, showing a beautiful greenish blue colour. Though of pure gold, deposited chemically,. the actual amount of gold used in filming-a surface is stated to be extraordinarily economical.. Among the exhibits is a convex mirror of about six inches diameter, and the cost of the gold *=ed in backing it was only one-eighth of a penny.

In a description of his process appearing in "Nature," Professor Gibson wrote: "Brilliant films have been deposited on suitably-prepared glass and. other surfaces. By reflected light they appear as massive gold, and by transmitted light show the characteristic colours of thin gold films. The films are capable of being polished, but they can be produced in such a mannes as to render this unnecessary. The thickness of the films' can be varied by altering the conditions of the reaction and the quantities: of the reactants. The necessary starting material being available, the pure gold films are actually more easily produced than those of silver, and are much more chemically inert. In spite of their opulent appearance as mirrors, the films of pure gold produced so readily and deposited on glass, etc., • may have considerable scientific application."