U371903.pdf (42.19 MB)
Animal chemistry from Lavoisier to Liebig (1780-1842).
thesisposted on 2015-11-19, 08:44 authored by Noel George. Coley
An account of some of the more important work of animal chemists in the late eighteenth and early nineteenth centuries, The search for the elementary composition of matter, after Lavoisier, soon led to the realisation that organic matter consisted principally of the elements carbon, hydrogen, oxygen and nitrogen (or azote), Destructive distillation--- the traditional method of analysis for organic matter--- merely produced a small number of 'proximate principles', oils and 'spirits', themselves compound. It was therefore necessary to devise methods of elementary analysis and this was done by Gay Lussac, Berzelius, Prout and especially Liebig, Chemists derived empirical fomulae from their analytical results, but there was no knowledge of molecular structure. The vital functions of digestion, assimilation, respiration, the generation of animal heat and excretion, linked through the medium of the blood, were all investigated by animal chemists, who sometimes in over-simplification compared the animal body to a steam engine. Most physiologists believed that chemists would be unable to account for life-processes without the concept of 'vital force'. Animal chemists, however, thought that the need for vitalism would diminish as chemical knowledge increased, but even Liebig still accepted a form of 'vital force' comparable with physical forces like gravity or electricity. In medicine animal chemistry had great practical value. It offered the physician a more scientific basis for the diagnosis and treatment of diseases and many physicians made significant contributions to animal chemistry whilst basing their medical practice upon the results of their chemical researches, microscopic anatomy, culminating in the cell theory of Schlieden and Schwann as well as the experiments of Magendie and Bernard on living animal organs were contemporary with animal chemistry. These techniques coupled with the concepts of colloid chemistry, ionic theory and conservation of energy, later combined to fom the basis for biochemistry.
Date of award1969-01-01
Awarding institutionUniversity of Leicester