From:
Sir John Herschel
To:
Robert Hunt
Date:
[1842-12-9 or later]
Source of text:
RS:HS 25.14.15
Summary:
Is anxious for some means to be developed to get a measurable quantity [preferably by weight] from the action of a beam of light on a surface. JH has been experimenting in photography with 'flouric' compounds.
Contributor:
John Herschel Project