120 Mr. T. Hopkins's Obsei-vations on Malaria. 



of an excess of steam in the atmospiiere, to have registers 

 kept of the thermometrical, hygrometrical, and barometrical 

 states of the air wherever malaria as found to prevail. It 

 would be also more satisfactory if the force and direction of the 

 wind were noted. Such registers may possibly exist at present, 

 but so little attention has been paid to hygrometry, as to make 

 it unlikely that any should be found that would be satisfactory 

 in the detail. The object of the greatest importance is to ascer- 

 tain the dew-point, that being the point at which evaporation 

 ceases from substances of equal temperature, and from this 

 to any higher temperature is to be deduced the energy of 

 evaporation. Possessed of registers of thi^ description, it 

 would be possible to exhibit scales of the drying powers of 

 the air at all temperatures that are found most conducive to 

 health. Physicians might then be enabled to direct patients 

 to remove to a more moist, or to a dryer atmosphere, as par- 

 ticular cases might require. New modes of prevention and 

 cure might also be devised, such as exposing the patients to 

 strong currents of air, drying the air by heating it, or even 

 by taking the steam out of it by exposure to hot salt, lime, 

 &c. &c. Exudation in a steam or hot air bath might be tried 

 as a succedaneum to evaporation. These are however only 

 speculations, and facts are the things wanted. The object of 

 the writer of this paper has been to invite attention to the 

 subject, in order to obtain the facts requisite to the formation 

 of a more conclusive opinion. 



Mean monthly Hygrometrical Return for the year 1832, in the 

 Island of St. Vince?it, as given i?i the Official Report. 



Jan. Feb. Mar. April 



68-68 67-14 67-99 67-93 



May. i June. July 



69-30 69-25 70-25 



Aug. Sept. 



Oct. I Nov. Dec 



69-66,69-69 69-39 69-41 67-31 



A Table of the Deaths per 1000 of Strength, and the portion of 

 those 'who died of Fever, per Aniium, of the White Troops 

 in the West Indies, being the average of the returns for the 

 Ttioenty Years from 1817 to 1836, arranged in the order of 

 the Mortality. Taken from the Official Report from Tisoenty- 

 tiw Stations. 



The Bahamas .... 

 Savannah la Mar 

 Montego Bay .... 



Deaths in 

 1000. 



200 



200 



178—9 



Deaths by 

 Fever. 



150—7 



