PROTAGON

n. Prot'a2g-on. From irpuros, first, and aytiv, to lead. Fr., p. Ger., P. A complex body, Ci6oH3o8NsPO35, formiug most of the white substance of Schwann, and also said to be a constituent of red blood-corpuscles. It was regarded as identical with myelin by Liebreich, who first isolated it in the form of fine acicular crystals soluble in warm alcohol, f" Annal. der Chemie und " Pharm.," vol. cxxxiv, p. 29 (K); Pniiger's Archiv," xii, 214 (K).J [s. 342]