_Editor’s notes._ (1) Confirmatory evidence of the correctness of the deductions made in this paper has begun to come in from many professional sources and notably from a famous child specialist who avers that children would follow the natural requirements in eating were it not for artificial food, bad example, and bad teaching. (2) In a report of a paper read before the _Société de Biologie_, Paris, France, March 15th, 1902, by M. Max Marckwald, of Kreuznach, “ON DIGESTION OF MILK IN THE STOMACH OF FULL-GROWN DOGS,” the following appears: “Hence these experiments confirm those of Horace Fletcher and Ernest H. Van Someren on the importance of prolonged mastication” (_translation_). Referring, as the latter statement does, to mastication (insalivation) of liquid, it gives an important suggestion relative to some probable causes of uncertain or defective digestion in human nutrition. THE CAMBRIDGE TESTS [In connection with a report of the Cambridge Examination the writer wishes to acknowledge the interest and assistance of Dr. Francis Gowland Hopkins, head of the Physiological-Chemical Department of the Physiological Laboratory of the University; Dr. George H. F. Nuttall, in charge of the Bacteriological Section of the Pathological Laboratory; Mr. Sidney W. Cole, Mr. Robert Barrett, and Dr. Hubert Higgins, both for practical work in the laboratory and in serving as test-subjects. To Dr. Higgins so much is due that it is difficult to measure. Since our first meeting in Cambridge, Dr. Higgins has been unremitting in his study of the subject and in consideration of its application to human betterment. Having the altruistic temperament inborn and not yet smothered by disappointment, the good doctor has consecrated himself to the service of poorer humanity, and his inspiration in so good a cause is wonderful motive power behind the native desire to do good. The statement of Dr. Higgins' experiences in pursuit of an Economic Nutrition is given in his own manner in the new edition of _Glutton or Epicure_, which is being published coincidently with this volume in the A. B. C. Life Series. At the time we were in Cambridge, Dr. Hopkins and Mr. Cole had just published their paper in the _Journal of Physiology_ (English), describing their isolation of the tryptophane element of the proteid molecule which had eluded chemists from the beginning. In tryptophane they found embodied the odourous indol and skatol which appear so offensively in the putrid decomposition of proteid. In the excreta of the test-subjects in our Economic-Nutrition-Inquiry these malodorous substances did not appear, and hence another question is opened up to investigation relative to the putridity of human excrement under ordinary conditions of carelessness, and the absence of putridity in the case of nutrition accomplished by aid of thorough buccal treatment of food preparatory to digestion.