WEIGHT AND HEIGHT. 541 



As regards weight, new-born boys are heavier than girls. An average 

 taken from 20,000 gives 6 Ibs. as the weight at birth; the weight of 

 maxima and minima have been 10 J Ibs. and 2 J Ibs. For about infan ts. 

 a week after birth the weight diminishes, owing to the effect of aerial 

 respiration. The difference in weight between the two sexes gradually 

 diminishes until about the twelfth year, when an equality is reached. 

 The maximum w*eight is attained about 40, and as 60 is ap- We - tt at dif _ 

 proached a diminution is perceived, which reaches 12 Ibs. ferent periods 

 at about 80 years, the stature likewise correspondingly di- 

 minishing by about 2| inches ; the female reaches her maximum weight 

 somewhat later, at about 50 years. The extreme limits of weight in 

 men are 108 Ibs. and 216 Ibs. ; in women, 87J Ibs. and 206 Ibs. The 

 mean weight at nineteen is nearly that of old age in both sexes. At full 

 development the male and female weigh almost exactly 20 times as much 

 as at birth. In the first year the infant of both sexes triples its weight. 

 It requires six years more to double that, and thirteen to quadruple it. 

 Immediately after puberty both sexes have half their ultimate weight. 

 Between the ages of 25 and 40 the mean weight of the male is 136J Ibs., 

 and of the female 120f Ibs. 



With respect to the relation between weight and height, if man increased 

 equally in all his dimensions, the weight would be as the cube Eelation of 

 of the height ; but since this is not so, development taking place height and 

 unequally, the proportion is not observed, and it is found that weig fc * 

 from the end of the first year to puberty the weights are as the squares 

 of the heights. M. Quetelet gives as an approximate rule that during 

 development the squares of the weights at different ages are as the fifth 

 power of the heights, the transverse growth being less than the growth 

 in height. The mean weight of a male, without reference to age, is 103f 

 Ibs. ; of a female, 93f . A similar calculation for the population of the 

 United States as that which has been given by this philosopher for Brus- 

 sels would give for the total weight of all Americans two thousand six 

 hundred and thirteen millions of pounds. 



The weight of an individual, considered without reference to age or 

 sex, is 98J Ibs. 



From birth until puberty the mode of life is essentially vegetative, all 

 the instincts having relation to the individual and corporeal development. 

 Except through the intervention of education, the desires of the child are 

 chiefly directed to the pleasures of mere vegetative existence, eating and 

 drinking ; and this, in savage races, is witnessed in a much more mark- 

 ed manner than in those that are civilized, in whom the manner of life is 

 affected through the intervention of parental care. In this particular it 

 may be remarked that maternal love is divisible into an in- Maternal love 

 stinctive and a moral affection, the former of a lower and of two kinds. 



