Donatpson, Law of lnnervation. 229 
corresponding area on the opposite side; to this sum was 
added the areas obtained by multiplying the length of each 
curved side (the ‘‘coast-line’”’), by a number equal to half the 
sum of the height of the side at the hip plus its height at the 
knee. 
The sum of the four areas thus obtained was considered as 
the total area of the skin of the thigh. By following the same 
steps, the total area of the skin of the shank was found. On 
coming to the foot, however, the method of determining the 
area required to be modified in order to include the additional 
surface represented by the toes. The original outline on the 
tracing paper gave the area of one side of the foot projected 
on a plane surface, to which, when doubled, should be added 
the amount represented by the elevation of the toes and that 
due to the thickness of the tarsus. 
To illustrate the method used, the following figure is 
given: | 
