Experience evinces, that this air is salubrious, and singularly beneficial in the cure of particular diseases ; on account of its being impregnated with a larger proportion of oxygen-gas, and containing less noxious vapours than that on land. Hence, a short voyage has often been successfully undertaken by consumptive patients, and such as were afflicted with asthmas, spitting of blood, and dropsies; especially if directed to a warmer country. These excursions have, likewise, been found very serviceable during the sickly season that annually prevails in the. West Indies, and other hot climates. Dr. Lind (Essay on the Diseases incident to Europeans In Hot Climates, 8vo. 1768) has therefore judiciously proposed a " floating factory, " or infirmary-ship, to be stationed at a small distance from the shore, as being an effectual mean of preserving numerous lives. He observes, that there are certain fevers, which require an immediate change of air; as, otherwise, the most powerful and appropriate medicines will prove ineffectual ; and, if a patient were removed to such vessel, as soon as the symptoms of the disease appear, he is of opinion, that the latter will not only be milder, but the cure will be facilitated: and the recovery of the patient more completely ensured. In consequence of this preservative measure, the constitution will be gradually inured to the climate; and thus be rendered less susceptible of injurious impressions, either from the atmosphere, or the exhalations of the soil.