450 C. R. BARI>EEN 



c. Heart weight and body weight 



In dealing with the relation of heart silhouette area to body 

 weight we are dealing with factors which can be objectively 

 studied on a large number of individuals. The determination 

 of the relation of the size of the heart silhouette to the volume 

 and weight of the heart is not open to so direct a study in human 

 beings. After death the heart can be weighed and the weight of 

 the heart may be compared with the weight of the body but unless 

 death has occurred from accident we are not likely to be dealing 

 with normal conditions. Conclusions as to what obtains in the 

 living must be cautiously applied from study of the dead. 



The relations of the size of the heart to the size of the body in 

 cadavers has been studied from various points of view. Among 

 the chief contributions to the subject are those of Boyd ('61), 

 who made an extensive study of the average weight of various 

 organs, including the heart in relation to body weight and age; 

 of Thoma ('82), who utilized mathematical theories of probability 

 in a valuable analysis of his own data and that of other investi- 

 gators in a study of the relation of the weight of the heart to body 

 weight; of W. Miiller ('83) who utilized extensive data in a study 

 of the relation of heart muscle weight to the weight of the heart 

 as a whole and of the relation of heart muscle weight to body 

 weight, height and age; of Beneke ('78) who studied the volume 

 of the heart substance from the standpoint of body length; of 

 H. Vierordt ('90) who has summarized the work of previous 

 investigators and added data of his own; E. Kress ('02) who 

 studied the weight of organs in children; and of Greenwood and 

 Brown ('13) who have applied modern mathematical methods 

 to a study of a small but carefully selected material. 



The studies of these and of numerous other investigators have 

 shown that there is a close correlation between the size of the 

 heart and the size of the body, due probably to the need of a 

 given mass of heart muscle to pump the blood to a given mass of 

 tissue. Greenwood and Brown conclude tha\; the correlation 

 between the weight of the heart and that of the whole body is 

 not much less than 0.5 and that the weight of the heart can be 



