Using the method previously described before this society,1 it has been possible, with the aid of Miss Sawyer and Mr. Stone, to measure the surface area of a total of 10 individuals. The “Linear Formula” previously described, when applied to these, gives an average error of 1.5 per cent. The chief limitation of the “Linear Formula” is that it involves the taking of 19 measurements. In the literature of the respiratory metabolism already published the only data given in regard to most of the subjects are the height and weight.On the basis of the actual measurement of the surface of 10 subjects of widely varying shape, formulas have been constructed on the plan of A = W1/a X H1/b X C, in which A is the surface area in square cm., W is the weight in kilograms and H the height in cm. and C a constant. Various formulas were tried, care being taken that 3/a + 1/b should always equal 2 in order that the formula might remain bi-dimensional. The formula A = W1/3 X H1/1 X C gave an average error of $$ 3.3 per cent....