474 



CHAMBERLAIN. 



It will be observed that Musgiave and Sison did not obtain readings during 

 the first twelve months which were as low as ours. Their figures after one year 

 of tropical residence coincide with what we found during the first year. In their 

 article these observers conclude that blood-pressure in the Tropics is materially 

 reduced. In view of the standards for temperate climates recognized by 

 Janeway,(3) Gallavardin,(4) Woley,(5) and Bachmann(7) it seems to us that the 

 average pressure of 124 millimeters found by Musgrave and Sison (with a 12.5- 

 centimeter armlet) is not low and that even the average of 115 millimeters could 

 not be considered so low as to be of much significance. 



SUMMARY OF INFLUENCE OF THE PHILIPPINE CLIMATE. 



Eeduced to the basis of a 12.5-centimeter armlet we found the average 

 blood-pressure for healthy white men in the Philippines to be 115 milli- 

 meters for those between 15 and 30 years of age and 118 millimeters for 

 those from 30 to 40 years old. These figures are little if any below 

 those to be expected in a temperate climate when a 12.5-centimeter cuff 

 is employed. The lowest readings were obtained in the first three 

 months of Philippine service. There was no progressive tendency for 

 the pressure to increase or to decrease with continued tropical residence 

 up to a little over three years, beyond which point our observations do 

 not extend. The pulse rate was constantly increased, averaging 9 beats 

 above the usual standard of 72 per minute. 



INFLUENCE OF SEASON ON THE BLOOD-PRESSURE AND PULSE RATE. 



The hottest part of the year in the regions where our observations 

 were made is in the second quarter, April, May, and June. The rains 

 usually begin in June or July and last till October or November. 

 December, January, and February are comparatively cool with a mean 

 temperature of about 25° C. (77° F.). Tables VII and VIII have 

 been prepared to show the influence of season on the blood-pressure and 

 pulse rate. It should be noted that in the 1909-Group the observations 

 began in the first quarter of the calendar year whereas in the 1910-Group 

 they commenced in the second quarter. The individual observations 

 could not of course all be made on the same date. In fact they are 

 spread over a period of about six weeks, but the majority were made in 

 the middle month of the designated quarter. 



Table VII. — Average systolic Hood-pressures and pulse rates for 587 men of the 

 1909-Group, the 4 observations on each man being arranged by season. (12.5- 

 centimeter armlet.) 



Observation. 



First 



quarter 



1909. 



Second 



quarter 



1909. 



Third 



quarter 



1909. 



Fourth 



quarter 



1909. 



Blood-pressure _ 

 . Pulse rate 







.__ millimeters.. 



116 

 82 



Ill 



88 



114 



87 



116 



83 













