Letter from Georg Brun, 3 Charlotte Muncksvej, Copenhagen, to Henry Barcroft [Queen's University, Belfast] Attached to a letter from 29 January [HB/14/58]. Discusses articles that Barcroft has asked to obtain. 'As to the problem we are discussing it certainly looks as if it cannot be solved on the basis of the available experimental data' - describes his experiments showing dilation of small arteries and constriction of an arteriole. Concludes that 'a normal blood-stream...seems to be indispensable for producing the paradoxal adrenaline effect...the fenomenon is of a reflex charachter'. Includes diagram of artery with cannula. 10 January 1947