244 ' On the Effects of Light and Air. 



Art. VI. — On the Effects of Light and Air in restoring the faded 

 Colors of the Raphael Tapestries; by Mr, Truli., — communi- 

 cated by Michael Faraday, Esq., D.C.L.; F.R.S.* 



April 21, 1839. 

 To the Editors of the Philosophical Magazine and Journal : 



Gentlemen, — You probably remember an exhibition in Jnly 

 last of certain Raphael Tapestries in the Haymarket, and the ex- 

 traordinary effect the exposure to light and air had had in restor- 

 ing and altering colors which had faded during centuries of ex- 

 clusion from these mighty agents. I have received letters from 

 the proprietor Mr. Trull, and if you think parts of them worth 

 publication at this time, when the action of light in the service of 

 the fine arts is so much dwelt upon, they are entirely at your 

 service. I am. Gentlemen^ yours, &.c. 



Michael Faraday. 



To Professor Faraday : 



Warwick-row, Coventry, March 19, 1839. 



Sir, — The interest you took in observing the changes of color 

 in the Raphael Tapestries, after being exposed to light in London 



me 



nary effects since produced, by the simple means suggested by 

 yourself and other scientific gentlemen, of a more perfect expos- 

 ure to light and air, which have for the last seven months been 



obtained, in a finely situated factory here. 



I feared to trespass on your valuable time, but could not resist, 

 after hearing of the great pubhc interest now excited by the new 



process, called, I believej "sun painting," 



dispell 



ing the damp, clearing up the colors, and reproducing others,^ ob- 

 scured by the effects of many years' close packing up in boxes. 

 I regret not to be able to make scientific remarks on the progress 

 of the recovery, which others acquainted with chemistry might 



■ 



have done. 



The results cannot fully be appreciated but by those who re- 

 collect the work when up in London, where the first effects of 



change vmexpectedly commenced. 



The greens had all become blue ; you, Sir, anticipated a return 



to the original tints, which has, almost throughout, taken place. 



* From the Lon. and Ediu. Phil. Mag. and Jour, of Science, June, 1831) 



