An account of the experiment made at the desire of the Lords Commissioners of the Admiralty, on board the Union hospital ship, to determine the effect of the nitrous acid in destroying contagion, and the safety with which it may be employed. In a letter addressed to the Right Hon. Earl Spencer, &c. &c. &c. By James Carmichael Smyth, M. D. F.R.S., Fellow of the Royal College of Physicians, and Physician Extraordinary to His Majesty, published with the approbation of the lords commissioners of the Admiralty.