FIG. 3.-a-b. Original check group.-Received institutional diet plus supplementary feeding, and gained. Upper broken line, normal expectation for age-weight relationship. Lower broken line, normal expectation for height-weight relationship. Solid line, growth curve.

FIG. 3.-C. Original check group.-Received institutional diet plus supplementary feeding, and gained. Upper broken line, normal expectation for age-weight relationship. Lower broken line, normal expectation for height-weight relationship. line, growth curve.

Solid

FIG. 4.a-b. Original milk group.- Received milk throughout experiment and gained remarkably, Upper broken line, normal expectation for age-weight relationship. Lower broken line, normal expectation for height-weight relationship. Solid line, growth curve.

FIG. 4.-C.

C.

Original milk group.-Received milk throughout experiment and gained remarkably. Upper broken line, normal expectation for age-weight relationship. Lower broken line, normal expectation for height-weight relationship.. Solid line, growth curve.

Chairman CUMMING. I think it will probably be necessary for us, in view of the important papers which are to follow, to have the discussion at the end of the reading of the formal papers, so that the gentlemen who have prepared papers will be sure to be able to read them.

It is unnecessary for me to introduce to you Dr. L. B. Mendel, of Yale University. Professor Mendel is one of the pioneers in this work. We all know about the work of Doctor Mendel in showing the value of vitamin A. [Applause.]

MILK AS A FOOD.

LAFAYETTE B. MENDEL, Ph. D., Sc. D., Sterling professor of physiological chemistry, Yale University, New Haven, Conn.

The recognition of milk as a food of unique value for the dietary of man is not new in the literature of the science of nutrition. In the "Bridgewater Treatise on Chemistry, Meteorology, and the Function of Digestion," printed in Philadelphia in 1834, Prout stated, after pointing out that "a diet to be complete must contain more or less all of the three staminal principles," the albuminosa, saccharina, and oleosa:

The composition of the substances, by which animals are usually nourished, favours the mixture of the primary staminal alimentary principles; since most of these substances are compounds, of at least two, of the staminal principles. Thus, most of the gramineous and herbaceous matters contain the saccharine and the glutinous principles; while every part of an anima! contains at least albumen and oil. Perhaps, therefore, it is impossible to name a substance constituting the food of the more perfect animals, which is not essentially a natural compound of at least two, if not of all the three great principles of aliment. But it is in the artificial food of man that we see this great principle of mixture most strongly exemplified. He, dissatisfied with the spontaneous productions of nature, culls from every source; and by the force of his reason, or rather of his instinct, forms in every possible manner, and under every disguise, the same great alimentary compound. This after all his cooking and his art, how much soever he may be disinclined to believe it, is the sole object of his labour; and the more nearly his results approach to this object, the more nearly do they approach perfection. Even in the utmost refinements of his luxury, and in his choicest delicacies, the same great principle is attended to; and his sugar and flour, his eggs and butter, in all their various forms and combinations, are nothing more or less, than disguised imitations of the great alimentary prototype milk, as furnished to him by nature. (P. 260.)

Subsequently the foremost trend of the scientific study of milk for many years lay in the direction of compiling analyses of this prod uct with special reference to the content of one or more of the proximate principles or foodstuffs therein. As new or improved methods of chemical examination of organic fluids were introduced. additional data were accumulated with respect to the proportions of water, proteins, sugar, inorganic salts, and particularly the fats in milk. The technical procedures gradually became standardized so as to permit the speedy execution of such analyses. At first the reports of the study of milk contained the summary of a few dozen of estimations; presently it became customary to bring these together by the hundreds, until at length the facts respecting the composition of milk appeared to lack real scientific respectability unless they were based upon literally thousands of analyses. This is characteristic of many "standardized investigations." To one who surveys the subject in retrospect it must seem strange that so much energy was expended in many laboratories upon the proximate analysis of milk when so much of far greater import remained to be discovered. Perhaps one reason for what has happened lay in the quantitative aspects of the subject. With 98 per cent or more of the constituents of milk recognized, the seemingly insignificant unidentified remainder made a lesser appeal to the investigator.

The experience of more recent years, however, has in striking ways taught the importance of "little things" in nutrition. For ex