Jan. 1. 1853.] 



NOTES AND QUERIES. 



21 



all future operations Is in all lights easily dis- 

 cerned. In my instructions for printing from 

 collodion negatives, a form of iodized paper was 

 given, which, although very good, is not, I think, 

 equal to the following, which is more easily and 

 quickly prepared, exhibits a saving of the iodide 

 of potassium, and is upon the whole a neater 

 mode. 



Take sixty grains of nitrate of silver and sixty 

 grains of iodide of potassium ; dissolve each sepa- 

 rately in an ounce of distilled water ; mix together 

 and stir with a glass rod. The precipitate settling, 

 the fluid is to be poured away ; then add distilled 

 water to the precipitate up to four ounces, and 

 add to it 650 grains of iodide of potassium, which 

 should re-dissolve the precipitated iodide of silver, 

 and form a perfectly clear solution ; but if not, 

 a little more must be carefully added, for this salt 

 varies much, and I have found it to require 720 

 grains to accomplish the desired object. 



The fluid being put into a porcelain or glass 

 dish, the paper should be laid doAvn upon its sur- 

 face and immediately removed, and being laid 

 upon a piece of blotting-paper with the wet sur- 

 face uppermost, a glass rod then passed over it to 

 and fro ensures the total expulsion of all particles 

 of air, which will frequently remain when the mere 

 dipping is resorted to. When dry, this paper 

 should be soaked in common water for three 

 hours, changing the water twice or thrice, so as to 

 remove all the soluble salts. It should then be 

 pinned up to dry, and, when so, kept in a folio 

 for use. I have in this manner prepared from 

 sixty to eighty sheets in an evening with the 

 greatest ease. It keeps good for an indefinite 

 time, and, as all experienced photographers are 

 aware, unless you possess good iodized paper, 

 which should be of a primrose colour, you cannot 

 meet with success in your after-operations. Io- 

 dized paper becomes sometimes of a bright brim- 

 stone colour when first made ; it is then very apt 

 to brown in its use, but tones down and improves 

 by a little keeping. 



To excite this paper, dissolve thirty grains of 

 nitrate of silver in one ounce of distilled water, and 

 add a drachm and a half of glacial acetic acid; of 

 this solution take one drachm, and add to it two 

 ounces and a half of distilled water. The iodized 

 surface of the paper may then be either floated 

 on the surface of the aceto-nitrate of silver or 

 exciting fluid, and afterwards a rod passed over, 

 as was formerly done in the iodizing, or the aceto- 

 nitrate may be applied evenly with a brush ; but 

 in either instance the surface should be immedi- 

 ately blotted off"; and the same blotting-paper 

 never used a second time for this, although it 

 may be kept to develop on and for other pur- 

 * poses. It will be scarcely needful to observe that 

 this process of exciting must be performed by the 

 light of a candle or feeble yellow light, as must 



the subsequent development. The excited paper 

 may be now placed for use between sheets of 

 blotting-paper ; it seems to act equally well either 

 when damp or when kept for many hours, and I 

 have found it good for more than a week. 



The time for exposure must entirely depend 

 upon the degree of light. In two minutes and a 

 half a good picture may be produced ; but if left 

 exposed for twenty minutes or more, little harm 

 will arise ; the paper does not solarise, but upon 

 the degree of image visible upon the paper de- 

 pends the means of developing. When long ex- 

 posed, a solvent solution of gallic acid only ap- 

 plied to the exposed surfaces will be suflicient; 

 but if there is little appearance of an image, then 

 a free undiluted solution of aceto-nitrate may be 

 used, in conjunction with the gallic acid, the 

 former never being in proportion more than one- 

 third. If that quantity is exceeded, either a 

 brownish or an unpleasant reddish tint is often ob- 

 tained. These negatives should be fixed by im- 

 mersing them in a solution of hyposulphate of 

 soda, which may be of the strength of one ounce 

 of salt to eight ounces of water — the sufficiency 

 of immersion being known by the disappearance of 

 the yellow colour, and when they have been once 

 immersed they may be taken to the daylight to 

 ascertain this. The hyposulphate must now be 

 perfectly removed by soaking in water, which may 

 extend to several hours ; but this may be always 

 ascertained by the tongue, for, if tasteless, it has 

 been accomplished. If it Is deemed advisable — 

 which I think is only required in very dark over- 

 done pictures — to wax the negative, It is easily 

 managed by holding a piece of white wax or 

 candle in front of a clean Iron rather hot, and 

 passing It frequently over the surface. The super- 

 abundant wax being again removed by passing it 

 between some clean pieces of blotting-paper. Al- 

 though the minuter details can never be acquired 

 by this mode which are obtained by the collodion 

 process. It has the advantage of extreme simpli- 

 city, and by the operator providing himself with 

 a bag or square of yellow calico, which he can 

 loosely peg down to the ground when no other 

 shade is near, to contain spare prepared papers, 

 he can at any future time obtain a sufficient 

 number of views, which afterw-ards he can de- 

 velop at his leisure. 



It requires no liquids to be carried about with 

 you, nor is that nice manipulation required which 

 attends the collodion process. 



The wax-paper process has been extolled by 

 many, and very successful results have been ob- 

 tained : the paper has the undoubted advantage of 

 keeping after being excited much longer than any 

 other; but, from my own experience, just so much 

 the weaker it is made, and so as to safely rely upon 

 Its long remaining useful, so It is proportionally 

 slower in Its action. And I have rarely seen from 



