Mr. Cundell on the practice of the Calotype Process. 329 



ought instantly to be removed into a dish of water ; five or ten 

 seconds at the most is as long as it is safe at this stage to leave 

 the paper to be acted upon by the gallo-nitrate; in that space 

 of time it absorbs sufficient to render it exquisitely sensitive. 

 The excess of gallo-nitrate must immediately be washed off^ 

 by drawing the paper gently several times under the surface 

 of water, which must be perfectly clean; and being thus washed, 

 it is finished by drawing it through fresh water, two or three 

 times, once more. It is now to be dried in the dark in the 

 manner described in § 19, and when surface-dry, it may either 

 be placed, while still damp, in the camera, or in a portfolio, 

 among blotting-paper, for use. If properly prepared, it will 

 keep perfectly well for four and twenty hours at least, pre- 

 serving all its whiteness and sensibility. 



24-. The light of a single candle will not injure the paper at 

 a moderate distance ; but the less the paper, or the exciting so- 

 lution, is unnecessarily exposed, even to a feeble candle-light, 

 the better. Common river or spring water answers perfectly 

 to wash the paper, distilled water being required for the silver 

 solutions only. Stains of "gallo-nitrate," while recent, may 

 be removed from the fingers by a little strong ammonia, or by 

 the cyanide of potassium. The third process is that of 



25. The Exposure in the Camera, — For which, as the ope- 

 rator must be guided by his own judgement, few directions 

 can be given, and few are required. He must choose or design 

 his own subject; he must determine upon the aperture to be 

 used, and judge of the time required, which will vary from a 

 few seconds to three or four minutes. The subject ought, if 

 possible, to have a strong and decided effect; but extreme 

 lights, or light-coloured bodies, in masses, are by all means to 

 be avoided. When the paper is taken from the camera, very 

 little, or more commonly no trace whatever, of a picture is vi- 

 sible until it has been subjected to the fourth process, which is 



26. The bringing out of the Picture, — Which is effected by 

 again applying the "gallo-nitrate" in the manner directed in 

 § 21. As soon as the paper is wetted all over, unless the pic- 

 ture appear immediately, it is to be exposed to the radiant heat 

 from an iron, or any similar body, held within an inch or two 

 by an assistant. It ought to be held vertically, as well as the 

 paper ; and the latter ought to be moved, so as to prevent any 

 one part of it becoming dry before the rest. 



As soon as the picture is sufficiently brought out, wash it 

 immediately in clean water to remove the gallo-nitrate, as di- 

 rected in § 23 ; it may then be placed in a dish by itself, under 

 water, until you are ready to fix it. The most perfect pictures 

 are those which " come out " before any part of the paper be- 



