Pyridine
C₅H₅N, a liquid, colorless when pure, possessing a characteristic and unpleasant odor. Boiling point, 115° C. Obtained in the distillation of coal tar. Being strongly basic, pyridine combines with the sulphuric acid used in the process of purifying coal tar products. On addition of soda to the acid solution, pyridine is liberated, and is isolated by fractional distillation. Pyridine is used as a denaturant for alcohol, and as a solvent in rubber, paint and other industries.