Copy, letter from Ida Smedley MacLean, of Admiralty Laboratories, to Sir Frederic Nathan of the Ministry of Munitions Reports on the results of their experiments. Notes that adding malted barely to the chestnuts has prevented frothing and improved yield of oil -- further experiments were not as successful, probably due to mould -- thinks that the high proportion of sugar in chestnuts may have caused the increased yield after the addition of malted barley. 20 July 1917