SYSTOLIC BLOOD-PRESSURE AND THE PULSE RATE. 



477 



carried on out of doors. The exercise was as fai* as practicable the same 

 for the two complexion types. On comparing the table with the pre- 

 ceding one, which deals with the same men when at rest, it is clear 

 that the result of exercise was to raise the blood-pressure by an average 

 of from 7 to 9 millimeters, and the pulse rate by an average of 7 

 beats. This is what would be expected in the case of healthy well- 

 trained men engaged in moderate out-door work. When we come to 

 compare the two complexion types it will be seen that both pulse rate 

 and blood-pressure are slightly higher for the brunettes. However, the 

 average differences are so small that they are probably of no importance, 

 and it is our opinion that variation in complexion does not produce 

 any significant change in the blood-pressure and pulse rate either at rest 

 or during exercise. 



INFLUENCE ON THE BLOOD-PRESSUEE AND THE PULSE RATE OF THE USE 

 OF ORANGE-RED UNDERWEAR AND HAT LININGS. 



Table XII was prepared as a part of the data which went to show 

 that orange-red under-gannents and hat linings for use in tropical 

 countries were of no value. 



Table XII. — Comparative average systolic blood-pressures and pulse rates for 

 29.^ tnen ivearing orange-red garments and 294 men wearing white ones, 1909- 

 Group.. {12. 5 -centimeter armlet.) 



Clothing. 



Aver- 

 age 

 age. 



First 



quarter 



1909. 



Second 



quarter 



1909. 



Third 



quarter 



1909. 



Fourth 



quarter 



1909. 



Average for 

 year. 



Pres- 

 sure. 



Pulse. 



Pres- 

 sure. 



Pulse. 



Pres- 

 sure. 



Pulse. 



Pres- 

 sure. 



Pulse. 



Pres- 

 sure. 



Pulse. 



Orange-red 



White 



Years. 

 25.4 

 25.4 



mm. 

 115 

 117 



82 

 82 



mm. 

 Ill 

 112 



88 

 89 



mm. 

 112 

 115 



88 

 87 



mm. 

 115 

 117 



83 

 83 



mm. 



113.6 



115.0 



85.1 

 85.2 











Exposure to ultra-violet rays is said to lower blood-pressure and 

 some have considered the sunlight in the Tropics to be richer in these 

 rays than it is in temperate regions. If such be the case it is con- 

 ceivable that the protection of the greater part of the body with a color 

 which intercepts the actinic rays of the solar spectrum might have some 

 effect on the blood-pressure. The experiment showed a lower blood- 

 pressure for those wearing the orange-red garments, but the difference 

 is so slight that, in our opinion, it should be attributed to chance rather 

 than to the influence of the clothing. At the different quarterly periods 

 the pressure of the orange-red group xanged from 1 to 3 millimeters lower, 

 and for the entire year the average for the orange-red group was 1.4 

 millimeters lower than for the white. Such slight differences are of 

 no significance. The averages for the pulse rate throughout the year 

 varied by only 0.1 of a beat. 



