<copy in WHFT’s hand of 07257>
Copy of a letter from Mr W. Carpmael
4 Old Square
Linc. Inn
Apr 28 / 56
Dr Sir
I entertain a strong opinion that no person has a right without your licence to use Gelatine mixed with Bichromate of Potash applied to a surface in the dark and then to take a picture by the Camera or otherwise by the aid of light and then to wash off by water the parts not acted on by light.
Yours vy truly
William Carpmael