Until quite recently the practitioner was compelled to rely for this purpose upon the various malt extracts upon the market, the diastatic power of which was so feeble that the service they rendered was but slight. What was needed, and for which many of the most patient investigators were searching, was a diastase which would do for the starchy elements of the food what pepsin does for the proteids. The digestion of food in man has been the subject of much patient and methodical study and investigation during the last two decades, notably by Ewald, Kellogg, Hayem, and Winter, and others, resulting in the placing of the therapeutics of disordered digestion upon an exact scientific basis. It is not, however, necessary for the purposes of this paper to go very deeply into the minutæ; a superficial survey will suffice. Digestion begins in the mouth with the act of mastication, the presence of food in the mouth, or even the thought of it, acting upon the salivary glands to produce a free flow of saliva, which, being thoroughly incorporated with the food by the act of mastication, exerts its peculiar influence upon the starchy constituents, converting them into dextrose, maltose, etc. This amylolytic action lasts but a short while, the ptyalin of the saliva being active only in neutral or slightly alkaline media; consequently when the food reaches the stomach and peptic digestion begins, its effect ceases. The saccharification of the starchy elements of the food before reaching the stomach serves to separate or disentangle them, as it were, from the proteids, and deliver the latter to the stomach in the condition most favorable to the action of the gastric ferment or pepsin. The stomach, after a variable length of time, during which the peptic ferments accomplish their allotted task more or less thoroughly and completely, delivers the resultant mass over to the small intestine, where the secretions from the pancreas, liver, and intestinal glands, by finishing the transformation of the starch begun before the stomach was reached, emulsifying the fatty constituents, etc., complete the complex work of digestion.