Antoine Lavoisier was a French chemist who is often referred to as the "father of modern chemistry." He is best known for his work on the law of conservation of mass and for establishing the foundations of modern chemistry. Lavoisier also played a key role in the development of the metric system and in the understanding of the role of oxygen in combustion. His work laid the groundwork for the understanding of chemical reactions and the development of the field of chemistry as we know it today.