In unhairing operations, the tanner desires a dis-solution of the epidermis with a minimum breakdown of hair and corium tissues. Comparatively little is known about the chemical structure of epidermis, due to practical difficulties in obtaining relatively complete, unmodified, uncontaminated samples of this tissue. Epidermis for this work was obtained from three animals by two methods calculated to yield a minimum of modification. These methods were (1) removal at less than 10°C with dilute sodium chloride solutions, with precautions taken against bacterial action, and (2) removal by the action of distilled water at 60°C. for a period of ten minutes.
This research project is concerned with liquid-liquid extraction. Specifically, it is a study of the mechanisms of solute transfer in spray towers. A theory is proposed which postulates the existence of three separate stages of solute transfer. These stages of extraction and the operating variables which seem to affect them are discussed.