163 
PHOTOGRAPHICAL SECTION. 
April 9th, 1867. 
J. Baxendell, F.R.A.S., Vice-President of the Section, in 
the Chair. 
Mr. Brothers read the following “ Note on Photography 
in 1787.” 
It is generally supposed that the earlier attempts to use 
nitrate of silver for producing pictures of lace, leaves, and 
other objects on white leather or paper were made by 
Wedgewood and Davy about the year 1802; but it will 
appear from the following extract that at least fifteen years 
earlier than the date named, and within ten years of the 
time when Scheele investigated the subject of the action of 
light on the salts of silver, the possibility of utilizing the 
action of light was known. The title of the book from 
which the extract is taken is “ Rational Recreations in 
Natural Philosophy,” &c., by W. Hooper, M.D., 1787 ; and 
the paragraph is headed “ How to print letters by sunlight.” 
“Dissolve chalk in aqua fortis to the consistence of milk, 
and add to that a strong dissolution of silver. Keep this 
liquor in a glass decanter well stopped, then cut out from a 
paper the letters you would have appear and paste the 
paper on the decanter, which you are to place in the sun in 
such a manner that its rays may pass through the places 
cut out of the paper and fall on the surface of the liquor. 
The part of the glass through which the rays pass will turn 
black, while that under the paper will remain white. You 
