In 1864, the German pharmacologist Oscar Liebrich presented a paper at a meeting in Giessen arguing that brain tissue was composed of a single giant molecule called "protagon." Any simpler lipids that chemists were isolating, Liebrich argued, were simply breakdown products of this primary, high-molecular-weight compound.
The protagon theory had quite an effect on Johann Ludwig Wilhelm Thudichum, a German-born physician and chemist who was working in London under contract to the medical officer of the Privy Council, John Simon. In an 1868 report to Simon, Thudichum wrote that he wanted to explore the theory further: "[Chemists] cannot form any conception of pathological processes of the brain matter before knowing [protagon's] chemical constitution of the whole." But when Thudichum started doing his own experiments on brain chemistry, he quickly became disenchanted with Liebrich's theory.
From 1865 to 1871, Thudichum carefully detailed the chemical constitution of the brain. He showed that ...
