Lecture by Dr. Pfeiffer on the Chemistry of Digestion.

Dr. Pfeiffer, the assistant at the laboratory in Organic Chemistry, delivered an exceedingly interesting lecture, last night, in Boylston Hall, on the Chemistry of Digestion. The lecture was delivered under the auspices of the Boylston Chemical Club, and will be followed by another on the same subject, Monday, Jan. 11, at 7.30. Dr. Pfeiffer spoke as follows:

The body cannot perform work for a long continued period without food of some sort to replace the loss of substance, in membranes, tissues, etc. And as the body is at all times wasting and weakening, the matter of food supply becomes imperative. Furthermore to be assimilated into the body, the food has to undergo a great chemical change. The observation of the manner in which this change is brought about, has been, of necessity, a matter of much uncertainty, although at present we are pretty well informed as to this change.

All substances used as food must contain elements of which the body is composed in such combination as to be digested easily. These foodstuffs occur in most cases mixed together with other substances more or less digestible, which may be divided into five classes: Inorganic Substances; Carbohydrates; Fats and Oils; Albuminoids; and finally Proteids. Of these foodstuffs the only absolutely essential are the Inorganic Salts and Proteids. As to the way in which these classes serve to keep the body nourished, little is known. The body seems to be the seat of a gradual grand combustion, taking place throughout its whole extent.

Dr. Pfeiffer then described rather hurriedly the digestive organs, to enable him to speak of the ancient ideas of digestion. Starting with the idea of its being a sort of putrefaction, ideas progressed through various stages until, by ingenious experiments, it was found that the object of the stomach was to dissolve the food. In the next lecture Dr. Pfeiffer proposes to treat of the processes of digestive fermentation.