468 CHAMBERLAIN. 



chronous pulse counts were made on 1,043 white men.^ Fiye hundred 

 and fifty-two blood pressure readings and 200 pulse counts were made 

 on 386 Filipinos, most of this work having been done by the Board, but a 

 part by some of the officers mentioned in footnote 3. When the number of 

 observers, all trained in laboratory methods, is considered, it will be 

 obvious that the influence of the personal equation in this work has been 

 reduced to a minimum. The great number of observations enables us to 

 avoid the errors inherent in a small series of cases. 



For convenience in reference the men examined in the orange-red 

 underwear tests will be denominated the 1909-Grroup and those exam- 

 ined during the blond-brunette observations will be referred to as the 

 1910-Group. 



CLASS OF PERSONS EXAMINED. 



All of the Caucasians examined were American soldiers, representing 

 a good class of healthy young adults. Diseased men were barred by the 

 stringent physical examination required at the time of enlistment. Fur- 

 thermore, all the men in both groups were looked over just before the 

 above mentioned observations began and any who appeared to be in ill 

 health were excluded. Very few of the individuals were over 40 or under 

 20 years of age and none were below 18 years. 



The Filipinos examined were from various tribes. One hundred were 

 soldiers of the Philippine Scouts and an equal number were from the 

 Philippines Constabulary. The remainder of the group was made up of 

 laborers, servants, and convicts. With the exception of a few of the 

 convicts, all were under 42 and the majority were less than 30 years of 

 age. A series of 20 Igorots living at Baguio (elevation 1,500 meters) 

 was also examined, but these are not included in the general averages 

 for Filipinos. Both the whites and the great bulk of Filipinos belong 

 to a class of men of good physical development and constantly engaged 

 in vigorous out-of-door work, with no special effort taken to protect 

 them from the sunlight. 



CLIMATE AND GEOGRAPHY. 



Only brief reference will be made to the climate and geography of the Archi- 

 pelago where these observations were made, because the subject is dealt with 

 quite fully in another report of the Board. (1) The islands on which the blood- 

 pressure readings were taken extended in latitude from 19° north to 6° north. 

 Except on high mountains the climate is everywhere tropical with a maximum 

 recorded temperature in Manila of 37°. 8 C. (100° F.) and minimum of 15° C. 

 (59° F.). 



' The medical officers who participated in the making of these observations on 

 pulse and blood-pressure were the following: Majors C. C. Collins and Roger 

 Brooke, jr.; Captains C. D. Cowles, G. L. McKinney, H. A. Philips, J. R. Barber, 

 Mahlon Ashford, E. G. Huber, H. M. Snyder, and W. L. Hart; and First Lieut- 

 enants Armin Mueller, M. C. Stayer, L. C. Garcia, and C. E. Fronk. 



