He was the last significant chemist of the "phlogistic" era. His scientific contributions: - Improvement of the method of extraction of phosphorus by distillation from vaporized urine, with chlorate of lead, sand and coal (1743) - Production of potassium cyanide and description of its properties in the treatment of metal salts (1745) - Zinc extraction through the reduction of "cadmiums" with coal dust (1746) - Discovery of the presence of sugar in local plants, particularly in beets (1747) - Introduction of the microscope as a tool for chemical research, which he used to identify sugar crystals (from 1747) - Obtaining formic acid (1749) - Distinction of formic acid from acetic acid through the reduction of mercury oxide with formic acid - Distinction between sodium and potassium through the color of the flame (1758)