Dec. 18. 1852.] 



NOTES AND QUERIES. 



587 



PHOTOGKAPHIC COBRESPONDENCE. 



The Collodion Proeess, as described by Dr. 

 Diamond. — I beg to thank you for your kind 

 replies to my two Queries respecting the iodide 

 of silver and the proto-nitrate of iron. I should 

 have done this earlier, but waited, hoping to 

 inclose some prints as specimens of my efforts; 

 but this the dull weather has hitherto prevented. 

 So soon as I may succeed, I will send some for 

 your inspection. I prepared my collodion, iodide 

 of silver, and proto-nitrate of iron in accordance 

 with the formulaj of Dr. Diamond, and have found 

 the results to be quite equal to any collodion, not 

 excepting the xylo-iodide, that I have obtained 

 from the London chemists. In short, I could not 

 desire a more clear and sparkling effect than I 

 have thus been enabled to obtain. I find, how- 

 ever, that the film, when dry, is not to be re- 

 moved without much rubbing, and wish it were 

 otherwise, as, after having applied a black varnish, 

 I often have removed the pictures and given them 

 to ladies for their albums, &c., and, being gummed 

 on to thin card-board, they were very available 

 for such purposes. I suppose that, probably, a 

 little more of the latter introduced into the mix- 

 ture might remedy this, and have accordingly 

 made some ; but, till the light be better, I cannot 

 tell whether or not I shall succeed. Now, where 

 the film may not be required to be taken off, this 

 quality will be highly advantageous, as there is 

 scarcely any chance of removing any portion of 

 the film in the manipulatory process ; and we 

 have much to thank Dr. Diamond for, in having 

 furnished us with so excellent a means for the 

 purpose. I find the proto-nitrate most delicately 

 beautiful in the effect it produces. 



Being but a novice in this art, and believing 

 that others just beginning to practise may meet 

 with like difficulties to those which I have expe- 

 rienced, and feeling that we ought to render any 

 little service to others that may be in our power, 

 I take the liberty to say that, after the glass has 

 been removed from the camera, if the thumb of 

 the right hand (which generally becomes somewhat 

 stained with the silver) touch the film, a fleck, 

 sometimes extending all the way up the glass, 

 will result. This may be avoided by doubling a 

 piece of note-paper, about an inch long and half 

 an inch wide, to hold the glass by whilst develop- 

 ing. Of course, when Dr. Diamond's plan, of 

 having the glass somewhat larger than the picture, 

 is used, this cannot occur : but, as this may not 

 always be convenient, it may be well to put my 

 fellow-tyros on their guard. Another defect has 

 often presented itself, viz. a great number of little 

 flecks of a yellowish tint, and which spoil the pic- 

 ture. These I have found may be avoided, by 

 rubbing briskly a clean glass, and dipping it in the 

 silver bath just previous to the immersing of the 



one required for the camera. To any one prac- 

 tised in photography these remarks are needless ; 

 but to us beginners every hint is, as I have found, 

 of some service ; and at all events. Sir, you will 

 excuse them for the motive which occasions them. 



T. L. Mebbitt. 

 Maidstone. 



Stereoscopic Pictures taken with one Camera. — 

 Will any of your photographic correspondents 

 kindly give, in your valuable little work, plain and 

 understandable instructions for taking stereoscope 

 pictures with one camera f The description of the 

 thing must be very clear indeed to be understood 

 by Ramus. 



Solution for positive Paper (Vol. vi., p. 562.). — 

 I beg to inform your correspondent C. E. F. that 

 in employing chloride of sodium in preparing 

 positive paper, I use twenty grains to the ounce 

 of water, a weaker solution than that which he 

 mentions. I float my paper upon it for two or 

 three minutes. The nitrate-of-silver solution I 

 employ in the next step is of the strength of forty 

 grains to the ounce. With these proportions he 

 will be able to procure positives of any shade, 

 from reddish-brown to sepia. 



I float my salted paper upon the nitrate-of- 

 silver bath for about two minutes, and when there 

 are no iron spots in the paper, I find it darken 

 very uniformly. W. F. W. 



After-dilution of Solutions. — May I be allowed, 

 as an humble operator of the photographic art, to 

 propose, through the medium of your valuable 

 journal, the following questions? 



Why the gentlemen who so kindly contribute 

 their photographic experience to " N. & Q.," after 

 they have sensitivised (if I may use the expression) 

 the waxed and iodized paper with a very strong 

 solution of aceto-nitrate, plunge it in distilled 

 water for a period corresponding to the length of 

 time they wish to preserve it : is not this equivalent 

 to diluting the sensitive bath ? In the early days 

 of photography, Mr. Talbot, I believe, used the 

 same process with his simply iodized paper; but he 

 soon found that diluting to the strength he re- 

 quired was not only more certain, but was alto- 

 gether more convenient and less wasteful of silver 

 solution. If there should be any reason of im- 

 portance for washing the paper, I shall feel greatly 

 obliged with a hint from any of yoiu- corre- 

 spondents on the subject. Simpucitas. 



7. Montague Place, Russell Square. 



[There is much common sense in the suggestion of 

 our correspondent. We should be glad to have his 

 views confirmed by the experience of practical pho- 

 tographers.] 



