1870.] 



on the Human Economy. 



525 



Table VI. — To contrast the number of respirations per minute (morning, 

 afternoon, and evening) in tropical and extra-tropical latitudes. 





Extra-tropical, between 

 lat. 50° and 26° N. ; aver- 

 age of 26 days. 



Tropical, between lat. 32° N. 

 and 13° S. ; average of 

 53 days. 



Morning (9 a.m.) | 



Afternoon (3 p.m.) 



Evening (9 p.m.) 



Number per minute. 

 North ... 14191 iqQQ 

 South ... 13-8 j "* i6 JJ 

 North ... 16-341 ,- 7d 

 South ... 14-75 j""' 10 '* 

 North ... 16-301 1P - PQ 

 South ... 15-06/- WW 



Number per minute. 

 13-15 



13- 65 



14- 18 





1507 



13-66 



Here two facts are apparent, — first, that the number of respirations 

 (morning, afternoon, and evening) are all less than in temperate regions ; 

 and, second, what is more specially designed to prove, viz. that in tropical 

 as in temperate latitudes the respiration is least frequent in the morning, 

 and gradually increases as the day advances. Thus at 9 a.m. it was 13-15, 

 at 3 p.m. 13*65, and at 9 p.m. 14*18. The Table further appears to 

 indicate that the difference between the number of morning and evening 

 respirations is not so great in the tropics as in colder latitudes. In the 

 former the lungs play a less active part as a heat-generator and eliminator 

 of carbonic acid and water. Hence the respiration is calmer and more 

 equable. Thus in the tropics there is only one respiration and a fraction 

 more in the evening; while in the temperate zone there is If nearly. 

 Had the season been winter instead of summer, and the weather colder, 

 the difference would have been greater. 



II. The Influence of Tropical Climates on the Pulse. 



Like the previously detailed experiments on the respiration, the present 

 were made during a voyage from England (lat. 51° N.) to Bahia (lat. 

 11° S.) and back, i. e. across the equator, and extend over 60 days (53 in 

 the tropics, and 7 in the latitude of England), during which the thermo- 

 meter ranged from 57° to 84° F. (27° F.). The observations were taken 

 thrice a day in the standing posture. Table VII. shows that, as in tempe- 

 rate latitudes*, the highest pulse of the day in the tropics occurs (though 

 by no means invariably) in the morning. 



Table VII. 



Highest pulse of the day in the f \ A p '™' *° g ^ 

 tropics during 53 days | g p ' M * 14 



* Dr. Guy, Guy's Hospital Reports, vol» iii. 

 VOL. XVIII. 2 R 



