Brain Chemistry and the French Connection, 1791-1841: An Account of the Chemical Analyses of the Human Brain by Thouret (1791), Fourcroy (1793), Vauquelin (1811), Couerbe (1834), and Fremy (1841) (review)

Modern texts of neurochemistry often mention Ludwig Thudichum, who did indeed perform the first reliable and fairly comprehensive chemical analyses of brain tissue (Chemical Constitution of the Brain, 1884). D. B. Tower’s book deals with the lesser-known analyses published by five French chemists in the half century between 1791 and 1841. These contributions originated in the years during and after the French Revolution, which also initiated an intellectual and scientific revolution. Thus, chemistry was becoming scientific as a result of pioneering work using improved analytical methods that produced increasing levels of knowledge and elementary and molecular concepts.

In an introductory chapter the reader is reminded of Cavendish, Lavoisier, and the birth of modern chemistry. The main part of the book contains the original texts of the five chemists, each preceded by an introduction with biography, academic affiliations, and general background information, and each followed by an annotated translation of the French text.

The first of these authors is Michel-Augustin Touret, who, working on the brains of exhumed corpses, reported in 1791 that they consisted of a soaplike material, reminiscent of spermaceti. Only two years later the famous chemist and revolutionary politician Antoine François de Fourcroy published a more reliable study, showing that fresh brain contains more than just one principle, and that phosphate is among them. His equally famous pupil, Nicolas Louis Vauquelin, reported in 1811 that brain tissue, in addition to “albumin” and salts, contains two or three lipids, no ordinary fat, and lipid-associated phosphate; furthermore, that white matter is distinguished from gray matter by its high lipid content. Jean-Pierre Couerbe in 1834 extended and refined Vauquelin’s results. Using ether in addition to alcohol as an extractant, he identified three more lipids including cholesterol. He was also the first to provide quantitative results and elemental analyses. Based on apparently increasing levels of phosphate in brains from “idiots” to “normal” to “alienated” people, he suggested a theory of phosphate as an excitatory principle. This clearly shows a motive behind performing analyses on a highly complex matter with still undeveloped means and knowledge. Finally, Edmond Frémy in 1841 published results that differed in part from Couerbe’s. ¹

Interesting as the five texts are, the modern reader is often at a loss when trying to understand what precisely was done and why. Unfortunately, Tower provides far too little help concerning nomenclature, chemical procedures, and conclusions. And some of the help he does offer is misleading—for instance, when “potasse” (potash) is defined as potassium carbonate, potassium hydroxide, or even potassium. Readers may also be disappointed by the final chapter, which talks about arsenic and Bordeaux wine instead of helping the reader interpret the work of the five brain chemists in the light of Thudichum or modern neurochemistry. Nevertheless, despite its shortcomings, this is an interesting and stimulating source book, complete with bibliography, a name-and-subject index, and illustrations.