A fine autograph letter signed by David Bruce on embossed headed note paper - Artillery Mansions Hotel, Westminster Phone No. Victoria 2003 - dated 20th Sep 1930, in blue ink on mottled grey/green paper with light central horizontal crease. In full: �Yours faithfully, David Bruce... (Retd) 20th Sept 1930� David Bruce (1855�1931) was a Scottish physician and microbiologist in the Royal Army Medical Corps. He identified the bacterium causing brucellosis�later named Brucella in his honour�and proved that Malta fever spread through infected goat�s milk while stationed in Malta. Bruce also helped investigate African trypanosomiasis (sleeping sickness). His discoveries greatly advanced tropical medicine and disease prevention in the British Empire.