August 26, 1920] 



NATURE 



829 



{Continued from p. 812.) 

 is to be taken as the normal weight of the animal, 

 if we are to determine its surface from its weight ? 

 This fundamental question has hitherto defied solu- 

 tion, but is now brought into the realms of exact 

 science,^ since the work of Prof. Dreyer and 

 Dr. Ainley Walker (2 and 7) has shown that in 

 animals and man definite relationships exist 

 between the trunk length, chest circumference, and 

 body weight of individuals in health, while no 

 accurate relationship, as has long been realised by 

 those familiar with the subject, can be traced 

 between standing height and body weight. 



The value of these measurements is enhanced 

 by the fact that, as anatomical data, they will be 

 practically immune from change in diseases which 

 may be accompanied by a loss of weight, and, 

 further, that as they bear a constant relation to 

 the body weight, so must they bear a constant 

 relation to the surface area of that animal. 



The relationships which have definitely been 

 shown to exist between "vital capacity," body 

 weight, trunk length, and the circumference of the 

 chest can be expressed by the following 

 formulae (8) : — 

 \yn 



(i) r^r-^ =Ki, where the power n is approximately 



t, though more accurately 0-72 ; 



(ii) —^ = K.,, where the power n is approximately 



2, though more accurately in males 2-26, in 

 females 2-3 ; 

 Ch« 

 (iii) -^ p =K3, where the power n is approximately 



2, though more accurately in males 197, in 

 females 2-54; 



while the relationships between body weight, 

 trunk length, and circumference of the chest, 

 respectively, can be expressed as follows : — 



W« 

 (iv) - =K4, where the power n is approximately 



A 



J, though more accurately in males 0-319, in 

 females 0-313 ; 



(v) p— =K5, where the power n is approximately 



J, though more accurately in males 0-365, in 

 females 0-284. 



In all the above formula W = net body weight 

 in grams, A = trunk length in centimetres, 

 Ch = circumference of the chest in centimetres, and 

 V.C. = vital capacity in cubic centimetres. 



The procedures for taking the above-mentioned 

 measurements, briefly described, are as follows : — 



(i) Body weight = net weight, without clothes, 

 in grams. 



(ii) Trunk length in centimetres is taken by 

 making the subject sit on a level floor with the 

 knees flexed, the os sacrum, spine, and occiput 

 being in contact with an upright measuring 

 standard. 



(iii) Circumference of the chest is taken at the 

 NO. 2652, VOL. 105] 



nipple level in males, and just under the breasts 

 in females, the subject being encouraged to talk 

 and breathe naturally while the measurement is 

 being taken. 



(iy) The "vital capacity" in cubic centimetres 

 is obtained by taking five consecutive readings 

 with a suitable spirometer. The subject is in- 

 structed patiently and carefully how to proceed, 

 and encouraged to make the maximum effort, the 

 highest reading of the five measurements being 

 recorded as the "vital capacity." 



The relationships established by Prof. Dreyer, 

 by the examination of individuals in perfect health, 

 provide standards with which an individual or 

 groups of individuals can be compared as regards 

 two fundamental attributes, namely, "physique" 

 and "physical fitness." These two attributes have 

 hitherto been subject to the widest possible in- 

 dividual interpretation, and even in the judgment 

 of one individual are liable to undergo monthly,- if 

 not diurnal, variations, dependent upon humour 

 and an infinity of changeable circumstances in 

 observer and observed. 



Applying the standards determined for in- 

 dividuals in perfect health, it is found, as might 

 have been expected, that different persons exhibit 

 considerable deviations from these standards, par- 

 ticularly in respect to their "vital capacity," 

 dependent upon their occupation and mode of life. 

 Thus persons living a healthy outdoor hfe exhibit 

 a greater " vital capacity " than persons following 

 a sedentary occupation, and when this deficiency 

 is not due to fundamental bodily defects it can 

 be remedied by properly regulated training and 

 outdoor life. 



Critical examination of the available data has 

 enabled Prof. Dreyer to grade the community, for 

 all practical purposes, into three classes. A, B, 

 and C, representing conditions of perfect, medium, 

 and poor physical fitness. A classification on such 

 lines is essential when any degree of accuracy is 

 required in the determination of the aberrations 

 from normal met with in disease. It would obvi- 

 ously be unjustifiable in disease (9) to apply A 

 class standards to the individual who, by reason 

 of his occupation and mode of life, belongs in 

 normal health to C class. The consideration of 

 this aspect of the question, however, need not 

 detain us longer, as being outside the scope of the 

 present article. 



It is extremely difficult in so brief an account to 

 do full justice to the immense significance and the 

 great possibilities which lie behind this recent 

 work of Prof. Dreyer's, but sufficient, it is hoped, 

 has been said to show that by systematic measure- 

 ment of "vital capacity " and the body measures 

 herein discussed, in adults and adolescents, it 

 should be possible to ascertain what detrimental 

 or beneficial effects environment and occupation 

 exert upon the development and health of the in- 

 dividual. Further, it is clear that most important 

 information, from the point of view of national 

 health, should become available in connection with 

 the methods employed to ameliorate the conditions 



