Experiments upon Magnesia Alba, Quicklime, and Some Other Alcaline Substances

This is the document where chemistry became a science. Written in 1755 by Joseph Black, then a young professor at Edinburgh, it records experiments that would reshape our understanding of matter itself. Black meticulously weighed substances before and after heating them, discovering that magnesia alba lost nearly half its weight when calcinated - a finding that defied the accepted wisdom of the time. Through careful quantitative analysis, he identified a previously unknown gas (what we now call carbon dioxide, which he termed "fixed air") being released during these reactions, marking one of the first times a gas was formally characterized through experiment rather than speculation. The work meticulously documents reactions between alkaline substances - magnesia alba, quicklime, and their variants - and various acids, revealing fundamental patterns in how these substances behave. Black's methods established the experimental standard for chemistry: measure everything, record precisely, let the data speak. This isn't merely a historical curiosity. It's the birth certificate of modern chemistry as a quantitative discipline.