5.28 Dr. Battray on the effects of Change of Climate, fyc. [June 16, 



tropics with the temperature of the air, and probably the activity of the 

 body and brain, both greatest in the afternoon, and again decrease with 

 these towards evening. The highest temperature (100°) occurred at 3 p.m., 

 the most oppressive part of the day in the equatorial calms, where the air 

 was most stagnant, humid, and hot (81° to 84° F.), with no breeze to cool, 

 by carrying off the surface heat, and facilitating evaporation. Their source 

 could not be dietetic, as little food was taken between 8 a.m. and 6 p.m., 

 and there was no rise after the latter hour. For the same reason it could 

 not be the result of local muscular activity. The totals show that 99° was 

 the most frequent temperature, and next to it 98 J°, while 99^° and 100° 

 form no less than 22 per cent, of the whole. Is not the blood itself likewise 

 somewhat warmer in tropical than in extra-tropical latitudes ? The range of 

 the temperature of the body in health is thus about 2° F. John Davy 

 gives it as from *5 to 1° F.* ; Eydaux and Brown Sequard at from 1° to 

 to 2J° and 3° F. The super- oceanic atmosphere, in which the present 

 observations were made, is never so highly saturated as to completely stop 

 evaporation from the cutaneous surface, otherwise the temperature of the 

 latter would rise much higher. Blagden and Fordyce bore a temperature 

 of 260° in the dry air of a heated oven, the temperature of their skin 

 rising 2J° F. only ; but when the air of the heated oven is so moist as to 

 hinder evaporation, the temperature of the body rises rapidly ; Ludwig 

 says as much as 7° or 8° F., and Obernier confirms this f. Observations 

 on this point are still wanted with regard to continental, littoral, and 

 insular equatorial climates, both dry and humid. 



The following Table, which shows the relation of the temperature of the 

 body to that of the external air in the shade, indicates a gradual though 

 trivial increase in the temperature of the former with that of the tempera 

 ture of the latter, proving that the one is slightly influenced by the other. 

 Thus at first it was 98° F. ; then 98*3, 98*6, 98-63, 98*8, 99'08 succes- 

 sively, as the temperature of the air rose from 57° F. to 84° F., the ave- 

 rage for the warmest part of the temperate zone being 98*3, and for the 

 tropics somewhat more, viz. 98*836. The Table further shows that 98° F. 

 is the prevalent temperature of the body in the temperate zone, as it oc- 

 curred in 24 out of 37 markings ; while in the tropics 99° F. is the most 

 frequent, and 98 J° and 99 J° nearly as frequent. These results correspond 

 closely with those of Dr. Davy J. 



* Parkes, * Practical Hygiene.' 



} As quoted by Carpenter (' Physiology '). 



t Ibid. 



