The different forms of collagen and gelatin

Abstract

The protein, collagen, is the chief constituent of the true skin or corium and it is also largely present in the organic matter of bones, cartilage and tendons. It is present in hide as a mass of interwoven fibres, each fibre being made up of smaller fibres, of microscopic dimensions, known as fibrils. Upon heating with water to 70° collagen slowly passes into gelatin, the rate of change being greatly increased if the collagen is first swollen in a suitable acid or alkaline medium. The most commonly used swelling medium is a suspension of lime, the lime acting both as a plumping and unhairing agent.