THORAX. 



1041 



the body. The function of the chest, how- 

 ever, as indicated by the quantity of air which 

 we can expel, is in strict relation to the mi- 

 nute difference of a single inch of stature, or 

 to 10 Ibs. of weight. It appears probable that 

 the function of an organ may be exactly re- 

 lative to the size of the body, increasing or 

 decreasing with it, while the organ itself bears 

 no visible relation of volume either to its own 

 activity or to the dimensions of the body. 



The greatest perpendicular depth of the 

 thoracic cavity, nearly corresponds with the 

 greatest lateral measurement ; or if the depth 

 be 8'7 the breadth is 9'7, and allowing for the 

 mobility of the base of the thorax, the depth 

 may yet more closely correspond to the breadth. 

 The average perpendicular depth of the female 

 thorax exactly corresponds with the average 



breadth, being 8'1 inches in both measure- 

 ments. The greatest antero-posterior dia- 

 meter in both sexes, i. e. from the sternum to 

 the deepest part of the great lateral groove 

 at the angle of the rib, is always less than 

 the greatest lateral breadth, being as 6 to 9 in 

 the male, and as 6 to 8 in the female. 



These diameters, however, in no way cor- 

 respond to the stature. A man, 5 feet 4 

 inches high, measured from the apex of the 

 chest to the base 10 inches, whilst 1 a man 

 of 5 feet 10 inches, only measured 7 finches 

 in the same direction, or the shorter man 

 exceeded the taller by 3 inches in the per- 

 pendicular depth of his thoracic cavity: 

 but the taller man could exceed the shorter 

 by a volume of 77 cubic inches of air at one 

 deep expiration. In fact, the whole of the 



Fig. 669. 



Area in Height. 

 Sup. in. ft in. 



36 



5 4 



50 5 10 



Height. Area in 

 ft. in. Sup. in. 



5 6 36 



5 10 63 



FEMALE. 



Sections of the Chest at the base. 



TABLE F. Average Measurements of the Thorax. 



(The mean of the measurements of fourteen males and six females, given in detail in Med. 

 Chirurg. Trans. 1846. Vol.29, p. 176.) 



In the males the left apex was highest in 6, the right in 6, and in 2 the summits of the apices 

 were on the same level ; in the females, the left apex was highest in 2, and the right in 4. 



VOL. IV. 3 X 



