Envelope. Annotated "CZ10 [processing annotation relating to nitrate negatives] . 4. Radon barts opk+2B radium. 1. 4 wks no penny, 2. 2 wks =with penny 3vpk, 3. 2 wks vpk = fog with curve, 4. ?2B= with penny. ?are 2 fortnight negs/same, why 4 wks not so dark. 1 contact with penny strong black and white. Use same developer at same temperature and develop for same length of time; all radium experimental negatives".
Radon. Annotated "2. 4 wks exposure 4/1/31-1/2/31. Penny certainly on the film all the time yet no sign of it on development ?reason".