"P. Misc" Photocopies of articles from an original folder labelled "P. misc", comprising: "Accuracy and Sensitivity of the Human Eye" by M H Pirenne and E J Denton, in 'Nature', vol. 170, number 4338, (20 December 1952); "Further studies of the positive visual after-image" by C A Padgham, in 'Optica Acta', vol. 4, (1957); "The Role of the Retinal Receptors in the Formation of the Positive Visual After-Image" by C A Padgham, in 'Vision Research', vol. 3, (1963); "The Absolute Sensitivity of the Eye and the Variation of Visual Acuity with Intensity" by M H Pirenne, 'British Medical Bulletin', (1953). 1952-1963