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June 12, 1868.] THE PHOTOGRAPHIC NEWS. 283 firi. 3. should the head be placed, and, if a full length, the les ground should be shown. A short person should be brought lower in the picture. In Figs. 3 and 4 the contrast i» shown. Fig. 4. It too often happens that the figure is made much too big for the picture. I have seen some cartes in which the head nearly touches the top of the picture and the toes the bot tom, so that when it was inserted in an album some part must be covered, perhaps a foot cut off, or perhaps half the head. This is done, I suppose, under a mistaken notion of the photographer’s that he is giving enough for the money, a principle to which I have no objection, but let the "enough” be in quality rather than in quantity, and he will be right. A carte-de-visite displaying proportion, taste, and a right feeling for art, is of much more value than a life-size picture that does not possess these desirable qualities, whether by painter or photographer. There has been a notion prevalent that all figures must be taken to scale; thus, if a six feet figure be represented in a carte-de-visite as three inches long (about the right pro portion), therefore a child three feet high must be repre sented as half that height, or one inch and a half. If it be necessary to make elevations of (say) a family, to send to friends at a distance to compare with others taken sometime before, to demonstrate the fact that the children are growing, then this method must be followed, but the photographer should never forget that it is his business to make pictures, and that a figure one and a half inches high will not fill a picture of the usual card size with anything like effect; [ therefore advise that a little licence should be taken in this particular, and that when a child is to be photographed all consideration of how much of the picture would be filled by a grown person, with the camera at a certain distance, be forgotten, and that nothing but the child, the object then before the photographer, should engage his thoughts. The same disregard of proportion exists amongst land scape photographers ; many would prefer to sacrifice effect rather than cut away a little of the foreground, and thus depart from their regulation size. o INKLINGS FROM THE WORKERS IN PHOTO GRAPHY. BY JOHN H. IALLENBACK. Urxmian Salt for Positive Printing and Measuring the Actinic Force of I)irect Sunlight. Tub above was a communication accompanied by a print from Prof. Joy to the Photographie Section of the American Institute. The positive print was obtained by sensitizing the paper with the oxyfluoride of uranium, and potassium, and formic acid. The print was made by Dr. H. Carrington Bolton, who was the inventor of this method ; the specimen was the first and only one taken by this process, and was very indistinct; it was brought forward at this early stage in order to fix the date of the invention. The picture is composed f the green fluorides of uranium and potassium, and is permanent. Formic acid produces no precipitate in a solution of oxyfluoride of uranium and potas sium ; but if the acidified solution be placed in the direct rays of the sun, decomposition begins immediately, and a green precipitate of the fluoride of uranium and potassium falls ; the precipitate is quite insoluble in water and dilute acids, and could be employed to measure the actinic force of the direct sunlight. The sensitizing bath is prepared by adding a few drops of formic acid to a tolerably concentrated solution of oxyfluo ride of uranium and potassium. The paper, while still wet, is placed upon the negative and exposed to the rays of the sun ten or fifteen minutes. The subject will be further in vestigated and reported upon. Mr. Newton gave me his process for making the rival Salomon prints which caused such a sensation. Mr. New ton’s pictures are pronounced the most beautiful ever made in this country; and as a great many inquiries have been made as to the manner of making the prints, I shall give it for the benefit of all who wish to advance in the art. The silver bath is the one first introduced by Mr. Newton. Silver Bath. Nitrate of silver 25 grains Nitrate of magnesium 25 „ Nitrate of potass ... 25 „ Acetate of lead 5 „ Water ... ... ... ... 1 ounce. After the bath is mixed and filtered he floated the paper for only half a minute, then dried and fumed it for twenty minutes with carbonate of ammonia. Toning Bath. He used several different carbonates, such as magnesium, lime, and baryta; but with his 25-grain bath it seems to make no material difference which is used. Of course he used sufficient chloride of gold of his own manufacture, and fixed with hyposulphite of soda, to which he added a few grains of chloride of ammonia; but Mr. Newton thinks pho tographers do not take time to make fine prints, and most all over-tone these by destroying the beautiful purples which are so essential in albumen prints, and for which Salomon’s are noted. I shall, in your next, endeavour to state other matters which were brought out at the meeting, and will close for the present with the hope that the new process with the oxyffuoride of uranium and potassium will call forth further