AUTHOR'S PREFACE. THE preparation of a new edition of my Animal Chemistry rendered it desirable, and even necessary, to subject to an experimental inquiry and criticism the chemical observations made, up to that period, in this department of the science. I was thus induced to engage in a series of researches, which have led me farther than I at first anticipated. The questions as to the nature of the organic acid diffused through the muscular system, and that of the other substances contained in that system, appeared to me so important for the right understanding and explanation of the vital processes, that I did not feel justified in proceeding with the revisal of my work until these questions had been, at least to a certain extent, experimentally answered. The present little work contains the analytical details of my investigation on these subjects, which, in accordance with the plan of the Animal Chemistry, could not be introduced into that work. As my experiments include the changes which flesh undergoes in its preparation for food, I trust that not only physiologists and chemists, but also the lovers of a rational system of diet, will find in the following pages many observations worthy of their attention. GIESSEN, 1st June, 1847. DR. JUSTUS LIEBIG. CONTENTS. SECTION I. On the methods of investigation to be pursued in Animal ... ... ... Chemistry Animal tissues and compounds act as ferments ... The changes going on in the body are little known page 1 ... 10 It is not tenable 16 Theories are never absolutely true, but only true for the Identity of composition not necessary Erroneous views deduced from the Proteine theory ... There is much to be done in regard to the constitution of Wöhler and Schlossberger on kreatine Investigation of the juice of flesh... Extraction of the soluble constituents of flesh The liquid always acid, even when mixed with blood ... |