In foreign Countries, when we meet with Hospitals where there are no Places for open Fires, but only close Stoves, different Contrivances may be used to renew the Air. Ventilators of different Kinds may be used, or Openings made in the Doors and Windows. In Winter 1761-62, some of the Wards in the Hospital at _Bremen_ which I attended had such Stoves. In order to keep up a free Circulation of Air in those Wards, I directed large Holes to be cut in the lower Part of the Door in each Ward, and two Grooves to be made on the Outside of the Door, above and below the Hole, parallel to each other, in which a Board slided; by means of which, the Hole could be either quite covered or only in Part, or left entirely open; and I directed a Casement, about eight or nine Inches square, to be made in the upper Corner of each Window. After the Fires were lighted, upon removing the Board which covered the Hole in the Door, and opening the little square Windows, a Current of fresh cool Air rushed into the Ward by the Door, while the heated foul Air found an Exit by the Windows. In very cold Weather, the Opening of the small Windows was sufficient; but in mild Weather, and in Summer, it was necessary to keep both open. The Wards should be daily fumigated by Means of Aromatics, or wetted Gunpowder thrown on burning Coals, put in an Iron Pot or Chaffern, or with the Steams of warm Vinegar placed in the Middle of the Ward. Dr. _Lind_ says, that although Cleanliness and a pure Air contribute much to prevent infectious Disorders, or to check them, yet that they of themselves are not always sufficient; but that he seldom or never knew a proper Application of Fire and Smoke to be unsuccessful in producing the happy Consequence of effectually purifying all tainted Places, Materials, and Substances[158]. [158] Dr. _Lind_ tells us, that the Ships of War in his Majesty’s Service are purified by Fire and Smoke, and gives the Process by which it is done; and he says, that he never heard of any Ship, which, after being carefully and properly smoked, did not immediately become healthy for the Men.--See _First Paper on Fevers and Infection_.--And he observes, that these Steams and Smoke, which are inoffensive to the Lungs, besides correcting the bad Quality of the Air, produce another good Effect; which is, to make both the Patients and Nurses desirous of opening the Doors and Windows for the Admission of fresh Air. _Ibid._ p. 51.