From Dr Archibald Billing   8 December 1855

My dear Sir

I have just looked out a few specimens which I had arranged for a similar purpose as yours, and I hope they may prove useful to you on Tuesday

Wishing you success in your laudable undertaking

Believe me | yours sincerely |Dr Billing

A.A.A. fragments of the same stone, one in its natural state, one coloured by nitrate of iron one by honey & sulphuric acid—

*B.B one by fire alone, one natural

*C.C. Do— , Do

*E. Common English yellowish brown flint changed by fire

*G. Changed by fire alone

*the tints varying merely from the quality of the stone— the agents the same