While much of this research followed established usage with regard to techniques, particularly in analysis, many of the procedures employed were either so fundamentally novel or important modifications of procedures previously described that, for a clear understanding of the data, it will be necessary to describe the techniques in considerable detail. One must assume that it is not permissible to publish data secured by an apparatus, technique, or method that has not been published or is not simultaneously published. On this basis, therefore, the report of this research must include the description of a considerable amount of new apparatus. On the other hand, in order to make the picture perfectly clear, it seems desirable to record, at least in brief, the methods employed for some of the simpler procedures, although no claim is made for originality in any of these well-known techniques.

The methods in the research as a whole may be classified under several heads: the control, preparation, sampling, weighing, and analysis of food; the collection, preservation, sampling, and analysis of feces and urine; the grosser physical measurements, such as weight, height, surface area, and body photographs; records of muscular activity so far as they could be made; clinical examination, including blood pressure, blood examination, records of pulse-rate and body temperature; measurement of the gaseous metabolism; quantitative measurements of muscular work; and measurements of the neuro-muscular processes. Under these several heads, the measurements of gaseous metabolism, body temperature, muscular work, and neuro-muscular processes were, in general, carried out with essentially new techniques, some of the apparatus and methods being specifically designed for this research. All of the techniques have been subjected to severe control tests, not only prior to but during the progress of this research.