Transfer of Negatives

1880 Scientific American  
SCIENTIFIC AMERICAN SUPPLEMENT, No. 239. 3807 ing, he is of opinion that forcing may be effected in an !llec-ammonic tartrate_ This reaction is, however, not in itself I touched when necessary, but not varnished, is then coated tric stove or inclosure containing an electric light, and that decisive, inasmuch as'I find that ferrous tartrate has itself I with the caoutchouc varnish, after the same fashion as it horticulturists may thus grow fruit of excellent aroma and developing properties. But
more » ... ng properties. But as ferrous phosphate is to some would be originally coated with collodIon, and is placed to flowers of great brilliancy without immediate solar aid. To extent soluble in a solution of ferrous sulphate, and as fer-. drain and dry for a few minutes. Afterwards, when the test what can be dgne practically the author has put down a . rous sulphate (in the form of development here under con-: benzine has sufficiently evaporated it is collodionized over steam en g ine and boiler at his country residence near Tun-sideration, namely, in the absence of soluble silver salt) is the caoutchouc varnish with the raw collodion, and again bridge Wells, and intends to lest the principles involved wholly without developing power, an opportunity offered: left for a little wiJile to dry; the film is then cut with a pen upon a "l>orking scale during the winter. The steam eugine itself of testing the question. And it proved that a solution knife all round the edge of the glass to the size required. which drives the dymlmo electric machine during the night obtained hy adding one of disodic phosphate to one of fer-Two pieces of any kind of paper are next taken of the same for the pmpose of giving light, is to be employed during the rous sulphate until a permanent precipitate began to form, shape as the plate, but of slightly larger dimensions than day in transmitting power through an electric conductor to undoubtedly possessed developing powers, though in a less those of the pellicle when removed from the plate, and one the farm for the purpose of carrying on small farming operade g ree. of these pieces is plunged in to a basin of water; it is placed, tions, such as turnip, chaff, and wood cutting, etc. Another The number of ferrous salts capable of developing the still wet, on the film. With a roller formed of a cylinder of interesting question which Dr. Siemens has set himself to latent image is very considerable. Singular anomalies are wood inserted in a piece of India-rubber tubing, the damp answer is to determine which portion of the rays constitut-often shown; a given salt, prepared in one way may develop, paper is made to adhere to the film; when now a corner of ing white light is efficacious in producing chlorophyl, while prepared in another it may have 110 such power. N or the paper is turned back and the corresponding corner of starch, and woody fiber, and which in effecting the ripening is it possible to form an opinion beforehand as to whether a the film carefully raised with the blade of a penknife and of fruit. For thi s purpose arrangements are in preparation given compound of ferrous oxide will exhibit this power or turned over it, the whole paper, by a slow but continuous to distribute the spectrum of a powerful electric light in a not; compounds nearly allied do not exhibit an alogies in motion, may he pulled off the glass, bringing the collodion darkened chamber over a series of similar plants exposed this respect. For example: ferrous phosphate and ferrous pellicle with it. . seriatim to the actinic, light giving, and thermal portions of meta-phosphate are active developers, while ferrous pyro-We have thus the negative removed from its original supthe spectrum. Some experiments have been made with phosphate has no flimilar power. port and stretched on the surface of a sheet of paper, to solar light in this direction, but no very conclusive results Among other ferrous salts possessing more or less developwhich it adheres by reason of the humidity of the latter. could be obtained, because the short periods of time during ing power, may be mentioned ferrolls hyposulphite (hydro-In this state it could be left to dry, and could then be used which the solar spectrum can be maintained steadily in the sulphate), ammonio-chloride, acetate, antimonio-tartrate, in its pellicular condition; but if it be desired to simply in same place are so short that the effects produced upon vege-etc. Ferrous formiate, which might naturally be expected vert the negative while keeping it attached to tbe glass, the tation have not been of a sufficiently decided character; to be a powerful developer, is almust, though not entirely, second sheet of pllper above mentioned must be taken and whereas, with the aid of electric light, the same spectrum destitute of the property. The most active agents found wetted in the same way as before. The first sheet, with the may be kept on steadily for a series of days without inter-were ferrous borate, phosphate, sulphite and oxalate, pellicle atta�hed, is then placed on a glass plate, the pellicle mi�sion. The author referred shortly to the lamp which he designed for this purpose, having a focus unchangeable in space, and without obstruction to the rays of light falling downward. There is no clockwork; the carbons are press ed forward either by their own weight or by the force of springs, the motion being checked by an abutment against which the carbon presses at the junction of its cylindrical
doi:10.1038/scientificamerican07311880-3807bsupp fatcat:dynxqw2rwzeudddukga6folyyy