Letter from [Alfred Joseph] Clark to [Archibald Vivian] Hill, regarding a paper 'The photochemistry of proteins with especial reference to the pharmacological and therapeutic actions of ultraviolet radiation, I and II' by [Joseph Stanley] Mitchell Paper reference code: B.150 Believes the pharmacological section of the paper to be 'exceedingly interesting'. Suggests publishing the pharmacological and physio-chemical sections separately. Does not think a paper this long would be widely read. Manuscript note adds that if the author will not split the paper into two, then it should be published in full. [Not published as a single publication, likely reworked as Part II of 'Photochemical reactions in monolayers: The photochemistry of proteins" co-authored with Erik Keightley Rideal, sent in May 1838 and published in Proc. A vol. 167, issue 930]. Received 21 May 1937 19 May 1937