It is fortunate that the common needs of digestion may be supplied from a limited range of food varieties. Milk is all-sufficient always for general supply of the nutritive requisites. In the plebeian potato, which has attained to royal rank as the result of the extensive experiments of Dr. Hindhede, of Denmark, in co-operation with Madsen the Faithful, has been found full nourishment for ten months, at least, when supplemented by butter or margarine to furnish the fuel supply. Even in this surprising revelation no academic prescription was infallible. Potatoes differ in nutritive value as much as 50 per cent. Fresh-cooked and well-cooked ones alone fill the bill of sufficiency, and full head-work in assuring easy digestion was made the first rule of the test. For four months I served as a check test-subject and speak from experience. Nothing is ever accomplished except by a division of labour and on the just division of responsibility depends the success of effort. Nature has given to us the head-end of responsibility. CHAPTER IX QUESTION PRESCRIPTION AND PROSCRIPTION The Protein Enthusiast--Doubting Thomases The only completely accurate prescriber of nutrition for living creatures is Mother Nature herself, and if she does not _pre_scribe anything by the undoubted approval of appetite she _pro_scribes it. One of the rules which have governed my quest for optimum human nutrition in the midst of the twentieth century food supply and other conditions, has always been to go to Nature for final advice in the matter. When I say "_Question_ Prescription and Proscription" I mean that the most positive prescribers of food have something in the food line or advice to sell, and they proscribe as positively anything that competes with their commercial product. My eyes were opened to this possible snare and delusion by a great doctor of medicine,[L] who is also one of the most ardent economists I have ever met--not a miser in any sense, but a religiously philosophical economist. He is almost as righteously indignant against any who use the trust which is placed in them by clients or patients for the selling of high-priced foods as he is at the makers, advertisers, retailers and prescribers of alcohol as a beverage. In his just opinion it is as wicked, or almost as wicked, to advise unprofitable extravagance of any sort as it is to prescribe poison. [L] Dr. M. Hindhede: Copenhagen, Denmark. To this discriminating philosopher food is the basis of health-wealth, and sacred to its divine usefulness.