The protagon phoenix

From 1865 to about 1910 studies of the chemistry of the brain were afflicted by the hypothesis that cerebral lipid matter consisted of a giant molecule from which all the simpler lipids were derived as breakdown products. In successive periods the main proponents of this 'protagon' theory were Oscar Liebreich, Arthur Gamgee and William Cramer. The theory was disproved by the careful and detailed studies of JLW Thudichum whose work on the brain was described in many papers, government reports, and two outstanding monographs. The controversy involved rough moments, generated by both sides, but by 1910, a few years after his death, Thudichum was fully vindicated in his opposition to the protagon concept and his classification of brain lipids became the accepted standard for biochemistry as a whole.     

Magendie and the chemists: the earliest chemical analyses of the cerebrospinal fluid

Having described the spinal fluid, Fran?ois Magendie (1783-1855) called upon a number of chemists in Paris to analyze the material, in the effort to decide if it was a special secretion of the nervous system or simply a filtrate of the blood. J.L. Lassaigne (1800-1859) and J.P. Couerbe (1805-1867) responded. Their results, and those of some earlier investigators, are described. In the ensuing years of the nineteenth century, other investigators similarly conducted analyses of spinal fluid, but these were usually of single constituents in poorly defined diagnostic conditions. In 1909-1912, William Mestrezat (1883-1928) took advantage of the recently introduced technique of lumbar puncture, which by now had become hospital routine, and introduced the modern era of systematic analysis of many components of the spinal fluid, correlated with specific disease states.     

An element of thought: phosphorus and mental philosophy in the nineteenth century

Georges Cabanis (1757-1808), through his writings on the relation of the physical and moral, or psychological, aspects of man, left a legacy that made the study of mental activity a part of physiology. His views on the importance of phosphorus to the function of the brain thrust that element into a prominent stream of research that involved many investigators in several countries. Although that particular stream eventually dried up, its influence remained: by the beginning of the twentieth century basic medical science had become well set on studies of the mind-body relationship.     

An Element of Thought: Phosphorus and Mental Philosophy in the Nineteenth Century

Georges Cabanis (17571808), through his writings on the relation of the physical and moral, or psychological, aspects of man, left a legacy that made the study of mental activity a part of physiology. His views on the importance of phosphorus to the function of the brain thrust that element into a prominent stream of research that involved many investigators in several countries. Although that particular stream eventually dried up, its influence remained: by the beginning of the twentieth century basic medical science had become well set on studies of the mind-body relationship.     

Light and enlightenment: Cabanis, ideology, and the role of phosphorus in the brain

When Georges Cabanis presented his views to the National Institute of France in 1797 on the physiological basis of human psychology, he introduced the concept that phosphorus was of special importance in the workings of the brain. The presence of phosphorus in that organ had only recently been described by A F Fourcroy, a finding that impressed Cabanis because of the association of light (phosphorescence) and heat (evolved during oxidation) with the element. Furthermore, he hypothesised that the electrical activity of the brain represented a parallel and interacting system with that of phosphorus. Cabanis was one of the leading exponents of "ideology", the principal school of philosophy at the time of the French Revolution. Ideology promoted the systematisation of knowledge in every sphere--social, scientific and medical, for example-- and Cabanis's views about cerebral phosphorus evolved from those teachings.     

Seventeenth‐ and eighteenth‐century commentators on the chemical composition of the brain

Abstract

The period between 1600 and 1800 was one of great change in the history of science, generally, and in the history of chemistry, specifically. It opened with Francis Bacon's visionary recognition of the benefits to mankind that would accrue from the expansion of scientia and closed with the overthrow of the phlogiston hypothesis. New chemical knowledge resulted from the efforts of the alchemists, especially the Paracelsians, and of the phlogistic philosophers, some of it recorded by writers of magic books (Thorndike, 1958; Camporesi, 1989). The authors of these works reflected ‘the general mentality… imbued with magic, occult beliefs, unreal suggestions, ‘voices’, and ‘rumours’, … ‘errors’ and ‘prejudices’.‘ In respect to brain chemistry there appeared, beside the fantastic, elements of fact that characterise this period as embracing the ‘pre‐history’ of neurochemistry.