390 



NOTES AND QUERIES. 



[No. 290. 



Mb. Lower will find some information in the — 

 « Memoirs of a Huguenot Family : translated and com- 

 piled from the original autobiography of the Rev. James 

 Fontaine, and other Family Manuscripts ; comprising an 

 original Journal of Travels in Virginia, New York, &c., 

 in 1715 and 1716, by Ann Maury . . . With an Appendix, 

 containing a Translation of the Edict of Nantes, the Edict 

 of Revocation, and other interesting Historical Docu- 

 ments. New York : George P. Putnam & Co., 10. Park 

 Place. 185.3." ^ ^^^^ 



PHOTOGBAPHIC COBBESPONDENCE. 



Photographic Notes— Never throw away your Collodion 

 — Being rather fond of testing by experiment the truth 

 of the results given by many photographers as to the 

 superior character of their respective collodions, I have 

 from time to time followed the various formulae given ; 

 some I have found to work well and up to their character, 

 others have fallen far short of the mark, and some almost 

 useless. Being unwilling last autumn to throw away the 

 remains of the various samples, consisting of some small 

 quantities of Home's, Bland and Long's, Thomas and 

 Hockin's, together with all those prepared by mj-self from 

 the formula of Dr. Diamond, Lyte, Wood, &c., amounting 

 to nearly fourteen ounces, I jumbled the whole together, 

 and gave it good and repeated .shakings; and I must 

 confess that now, after nearly six months' rest, it proves 

 the best negative collodion that I have ever met with. 



^ M. P. M. 



Amber Varnish. — Last summer I made an ounce of 

 amber varnish, according to Uk. Diamond's formula in 

 the Photographic Journal, and a most exquisite sample it 

 proved to be ; a few weeks since it was perfectly useless, 

 although securely kept during the interval ; and I have 

 again tried with new samples of chloroform, and the same 

 quality amber, to manufacture more, and cannot succeed. 

 After three days' maceration, and good shaking at intervals, 

 the chloroform does not appear to have dissolved any 

 portion of the resinous qualities of the amber. The amber 

 was of good quality, and consisted of the broken mouth- 

 pieces of meerschaum pipes. Pray will any of your 

 friends explain the why and wherefore. M. P. M. 



Dry Collodion. — Mr. Mayall communicated to the 

 AthencBum of Saturday last a new process, which he has 

 just completed, for using collodion dry. We have ven- 

 tured to transfer it to our columns, because every hint 

 from so practised a photographer as Mr. Mayall deserves 

 attention. 



The usual plain collodion is excited with 



(No. 1.) 3 grains iodide of cadmium. 



1 grain chloride of zinc. 



1 ounce collodion. 



i ounce alcohol. 

 Dissolve the chemicals in the alcohol, and then mix with 

 the collodion : or 



(No. 2.) 3 grains iodide of zinc. 



1 grain bromide of cadmium : or 



(No. 3.) 2 grains iodide of cadmium. 



1 grain bromide of cadmium. 



55 grain bromide of iron. 



5*3 grain bromide of calcium. 

 In the last it will be necessary to dissolve 1 grain of 

 bromide of iron in 1 drachm of alcohol, and use 1 fluid 

 grain of the solution. Similarly 3 grains of bromide of 



calcium must be dissolved in 1 drachm fof alcohol, and 

 use 1 fluid grain. The excited collodion will require to 

 stand a few days to completely settle. Decant intoX^^y 

 bottle to avoid sediment. Spread as usual. Kui-s 



Bath of Albuminate of Silver. 

 16 ounces distilled water. 

 1 ounce albumen. 



IJ ounce nitrate of silver (neutral). 

 l| ounce glacial acetic acid. 

 2'grains iodide of potassium. 

 The albumen and water must he well mixed first, then 

 the glacial acetic acid added ; shake up and stand three 

 hours, then the nitrate of silver in crystals, shake and 

 filter, stand twenty-four hours, then add the iodide of 

 potassium, filter again ready for use. Coat the plate as 

 usual with collodion, and use the albuminate of silver 

 bath as an ordinary silver bath ; wash in another bath ot 

 distilled water five minutes, then wash the back ot the 

 plate with common water, the front with distilled ; set the 

 plate aside to drv, vertical position, in a place free from 

 dust. It will keep three weeks. Expose in the camera 

 as usual, from two minutes to ten, according to the light, 

 diaphragm, &c. Pass into the silvering bath again three 

 minutes. Develope with 



6 grains proto-sulphate of iron. 



1 ounce distilled water. 



1 drachm glacial acetic acid. 



Wash, and fix with 



1 cyanide of potassium. 

 20 water. 

 It is about as quick as albumen in the camera. The albu- 

 minate of silver bath must on no account be exposed t» 

 daylight, nor the developing solution. Potassium and 

 ammonium salts will do to excite the collodion ; but it 

 will not keep so long as with the metallic iodides. 



Fading of Positives : Photographic Society.— The charge 

 which we have occasionally heard brought against the 

 Photographic Society, that it has done litt e for the art 

 for thi promotion of which it was specially instituted, 

 cannot hereafter be justly preferred. That bociety has 

 iust taken an important step, which all lovers of photo- 

 graphy must admit to be a step in the right direction. 

 It has appointed a Scientific Committee, consisting of 

 Mr Delamotte, Mr. Hardwick, Dr. Diamond, Dr. Percy, 

 Mr. Pollock, and Mr. Shadbolt, to investigate the perma- 

 nency of photographs, causes of fading, &c. 1 he tunds 

 of the Society are made applicable to the investigation; 

 and Prince Albert has contributed 50/. also to this special 

 purpose. We shall be glad to use our influence among 

 our photographic readers for the promotion of this im- 

 portant object; and we will take care that any faded 

 photographs sent to us for investigation by the Com- 

 mittee shall duly reach their destination. 



JSitpllti ta Minor dkueviti. 



Population ofDedham, U. S. (Vol. xi., p. 324 ). 

 — At the census of 1850, the population of the 

 "town of Dedham (Massachusetts), U. S.," was 

 4447, of whom 18 were free coloured persons. 

 But this bald answer would, I imagine, very pro- 

 bably mislead your correspondent J. B. The 

 term tovm in this, and most of the other states of 

 the Union, is equivalent, or nearly so, to our 



