Chitin Content of the Mandible of the Snail (Helix pomatia)

Abstract

THE presence of chitin in the above-mentioned organ has been indicated so far by means of colour reactions only, probably owing to the laek of material. During the course of another investigation, we came into the possession of 650 mandibles (1 gm.), and an acetolytic breakdown experiment was carried out. After boiling with dilute alkali and hydrochloric acid, the remainder weighed 70 mgm., and yielded upon the application of Bergmann's method 8 mgm. of colourless needles which were identical with octa-acetyl chitobiose: m.p. 290°, nitrogen content 4·4 per cent. The experiment shows that the presence of chitin can be proved in even minute amounts of natural substances.