Letter from Bernard Dyer, consulting chemist and public analyst, to Arthur Crossley, Secretary to the Royal Society Describes the definition of 'indispensibility' and his own position as an official agricultural analyst, a role which he says requires many years of experience -- notes that there has been 'a great exodus of young chemists to the war', and others are pressured to enlist -- thinks that there should be some ruling which could render indispensible workers 'immune from reproach' and some sort of badge to make their position clear -- comments on the urgent need for more analysts and does not think work can continue unless something is done. 16 November 1915