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 LXXVIII. Intelligence and Miscellaneous Articles. 



ENERGIATYPE, A NEW PHOTOGRAPHIC PROCESS. 

 BY ROBERT HUNT. 



V17"HILE pursuing some investigations, with a view to determine 

 ™ ™ the influence of the solar rays upon precipitation, I have been 

 led to the discovery of a new photographic agent, which can be em- 

 ployed in the preparation of paper with a facility which no other sen- 

 sitive process possesses. Being desirous of affording all the informa- 

 tion I possibly can to those who are anxious to avail themselves of the 

 advantages offered by photography, I solicit a little space in your 

 columns for the purpose of publishing the particulars of this new 

 process. All the photographic processes with which we are at pre- 

 sent acquainted, sufficiently sensitive for the fixation of the images 

 of the camera obscura, require the most careful and precise mani- 

 pulation ; consequently, those who are not accustomed to the nice- 

 ties of experimental pursuits are frequently annoyed by failures. 

 The following statement will at once show the exceeding simplicity 

 of the new discovery. 



Good letter-paper is first washed over with the following solu- 

 tion : — 



A saturated solution of succinic acid. ... 2 drachms. 



Mucilage of gum-arabic \ 



Water \\ ... 



When the paper is dry, it is washed over once with an argentine 

 solution, consisting of 1 drachm of nitrate of silver to 1 oz. of 

 distilled water. The paper is allowed to dry in the dark, and it is 

 fit for use. It can be preserved in a portfolio, and at any time em- 

 ployed in the camera. This paper is a pure white, and it retains its 

 colour, which is a great advantage. At present I find it necessary 

 to expose this prepared paper in the camera obscura for periods, 

 varying with the quantity of sunshine, from two to eight minutes, 

 although, from some results which I have obtained, I am satisfied 

 that, by a nice adjustment of the proportions of the materials, a 

 much shorter exposure will suffice. When the paper is removed 

 from the camera, no trace of a picture is visible. We have then to 

 mix together 1 drachm of a saturated solution of sulphate of iron 

 and 2 or 3 drachms of the mucilage of gum-arabic. A wide flat 

 brush, saturated with this solution, is now swept over the face of 

 the paper rapidly and evenly. In a few seconds the dormant images 

 are seen to develope themselves, and with great rapidity a pleasing 

 negative photographic picture is produced. The iron solution is to 

 be washed off as soon as the best effect appears, this being done 

 with a soft sponge and clean water. The drawing is then soaked 

 for a short time in water, and may be permanently fixed by being 

 washed over with ammonia, or perhaps better with a solution of the 

 hyposulphite of soda, care being taken that the salt is afterwards 

 well washed out of the paper. From the pictures thus produced, 

 any number of others, correct in position and in light and shadow, 

 may be produced, by using the same succinated papers in the ordinary 

 way, from five to ten minutes in sunshine producing the desired effect. 



