Sách nói: Familiar Letters on Chemistry

Justus von Liebig (1803-1873) was a German chemist who made major contributions to agricultural and biological chemistry and is known for his discovery of nitrogen as an essential plant nutrient. These letters “were written for the especial purpose of exciting the attention of governments, and an enlightened public, to the necessity of establishing Schools of Chemistry, and of promoting by every means, the study of a science so intimately connected with the arts, pursuits, and social well-being of modern civilised nations.” (Summary by Wikipedia and J.M. Smallheer)