Under a grant from the Royal Society, Bardswell and Chapman were engaged in research work for a period of seven years, and from time to time made reports to the society. This work is an abstract of these communications and represents the final report of their investigations. The conditions of these investigations were most favorable, because each worker was the medical superintendent of a large sanatorium. From their own experiences and from the results obtained by coworkers in Europe and America they deduce general principies of diets for consumptives and are able to state the comparative value of various foodstuffs. Their practical conclusions should be of value to superintendents of sanatoria, especially to those who are compelled to strive for economic efficiency in diets.