Sodium Hydroxide Solution: Normal Caustic Soda, 40 g per Litre (Sutton, 1904)

The standard normal (1 M) caustic soda solution for titration: 40 g NaOH in each litre. Make it a little too strong, check it against normal acid, bring it to exact strength and keep it away from the air, which it takes carbon dioxide from. Result: normal sodium hydroxide solution, its strength proved by titration. Source: F. Sutton, A Systematic Handbook of Volumetric Analysis (1904), p. 48. Picture: that page of the book.