Letter from Kenneth Mackenzie to J B S Haldane Letter from Mackenzie to Haldane enclosing a copy of Mackenzie's proposed research application and asking whether Haldane could assist with the publication of a paper on ultra-violet light by Mackenzie and H J Muller. <br /><br /> On the reverse of Mackenzie's letter is a copy of Haldane's response dated 15 March 1940 in which Haldane states that he is willing in principle to forward Mackenzie's paper to the Royal Society for publication. 29 Feb 1940