TALBOT6893

Ath^{m 1}
Saturday

Dear Grove

With respect to the claim² for the use of “liquids” I have enquired of M^r Henneman³ as a practical Photographer, whether he thinks that any person takes the photographic portraits without developing the image by immersion in a liquid? He says no one does, for in practise i[t] cannot be dispensed with.

I asked what liquids are practically employed he says that in paper photographic portraits the object being to obtain in y^e 1^st place a negative image on glass, gallonitrate of silver is the liquid generally employed, which is the one originally described by me, altho’ some persons prefer to use pyrogallic acid mixed with nitrate of Silver. He thinks there can be no doubt of the Employment of it by Laroche.⁴

The use of the salts of iron is chiefly confined to the production of positives on glass, or amphitypes as I call them⁵ – My receipt⁶ for making them in my last patent ⁷ indicated Sulphate of iron –

Yours truly
H. F. Talbot

I have read your interesting remarks on the Electricity of flame.