AMATEUR PHOTOGRAPHY. 



327 



sent me chloride of gold, another sent me 

 platino potassium proto chloride, and the 

 3rd sent me potassium chloride platinito. I 

 should like to know if the 2 latter are the 

 same as the chemical mentioned in Recre- 

 ation. Also, how they can be used to 

 tone silver prints? 

 J. Brachmann, Jr., North Yakima, Wash. 



ANSWER.. 



Your 2 varieties of platinum are practi- 

 cally the same, and will work well if dis- 

 solved as described in the Recreation 

 formula. You will find useful formulas 

 for using platinum in the American Aristo 

 Company's Manual, which is to be had free 

 of them at Jamestown, N. Y., or some- 

 times at dealers'. The platinum is gener- 

 ally used after a short preliminary gold 

 toning. — Editor. 



ON DEVELOPMENT. 



For testing an excess of alkali in sul- 

 phite : Take 18 ounces of sulphite solu- 

 tion 'to test 60 grains to the ounce. It re- 

 quires only 20 drops sulphuric acid to 

 change this to the acid form very 

 slightly. After you have added the 20 

 drops, and it is still alkali, add more until 

 your solution is acid, slightly. Just as 

 much as you add above 20 drops, 

 would he required to make your sul- 

 phite in proper form. The one thing nec- 

 essary is, not to overdo the thing. Add 

 just enough or not quite enough acid to 

 your sulphite solution to overcome the ex- 

 cessive alkali. There is no such thing as 

 neutral sulphite. I have never seen it. 

 Your sulphite must be slightly alkali, or it 

 would soon become sulphate, which is an 

 acid. — L. H. Hume, in N. E. Photog- 

 raphers' Convention. 



CHLORIDE OF COPPER. 



Please tell me where to get chloride of 

 copper. I have tried all the principal 

 drug and camera stores without success. 

 It seems to be something entirely new to 

 them. Also tell me how much hypo to 

 use with Aristo-platino paper to fix 24 

 pictures. 



J. Dewar, Spokane, Wash. 



ANSWER. 



Chloride of copper can be obtained in 

 any decent drug store. Maybe the clerk 

 who said he had none will oblige you 

 with 10 cents' worth of cupric chloride, 

 which is the other name for it. 



I don't know what sire prints you make, 

 so the exact quantity of hypo can not be 

 given. If you use one ounce of hypo in 

 10 ounces- of water it will fix 24 8x10 

 prints. Better use this quantity for any 

 size. — Editor. 



TO ELIMINATE HYPO. 

 The following may be helpful to many 

 who have not the advantage of running 

 water for washing photo plates and prints. 

 Get a piece of cork, about 4 inches square 

 and an inch thick; fasten to each side of 

 the cork at the center an ordinary clamp, 

 such as is used to secure cuffs to the 

 sleeve of a shirt. Fill a pail or tub with 

 water, fasten the negative at that end 

 where the clip in the holder retains it in 

 the little jaws of the cuff clamp, and place 

 it in the water. The cork will float and 

 hold suspended the plate, thereby allow- 

 ing the hypo to pour freely out from the 

 film. The reason for this is that hypo is 

 much heavier than water, so if anything 

 saturated with it is suspended in water the 

 hypo will of its own weight leave it. A 

 plate can be thus thoroughly cleansed in 

 a remarkably short time, and where one 

 has not the advantage of running water 

 this method is valuable. — The Camera. 



TO DRY NEGATIVES. 



For the quick drying of negatives or 

 gelatine prints, formalin is without an 

 equal. The film is so hardened that prints 

 may be handled in the wash without dan- 

 ger of sticking to one another or getting 

 scratched. 



We hear frequent complaints about pa- 

 pers sticking to the negative in the print- 

 ing frame. There would be no trouble 

 from this source if the negative had been 

 bathed in a weak solution of formalin, 

 which renders it entirely impervious to 

 moisture. When the paper that has stuck 

 to a negative can be removed by soaking, 

 which is not always the case, a silver 

 stain will be left on the negative. This 

 may be removed with a 5 per cent, solution 

 of ammonium persulphate. Both the 

 formalin and persulphate should be in 

 every workshop. Their uses are many. — 

 The Camera and Dark Room. 



A CAMERA TO FOCUS AT 6 INCHES. 

 Please tell me through Recreation if 

 there is any camera, film preferred, which 

 will focus up to 6 inches or less. If there 

 is none, what camera will focus the near- 

 est to any object and how near? Please 

 mention price. 



B. F. Dawson, Rhinebeck, N. Y. 



ANSWER. 



Six inches is getting too near your sub- 

 ject to make a picture comfortably. You 

 can obtain such a camera, if you really 

 need it, from the Century Camera Co., 

 Rochester, N. Y. It will require extra 

 long bellows and will cost not less 

 than $20 for 4x5 size, and more if film is 

 used. You can get an amplifier of Burke 

 & James, Chicago, that will fit your lens 



