On August 1, 1774, the British chemist Plister discovered oxygen when heating uranium oxide in a laboratory.

In the results of the research of gas chemistry, Plister was most important to the discovery of oxygen. In 1774, he got a large lens (lens) and began to study the various gases released by certain substances at the high temperature of the producer of the lens. Among the substances he studied were the "red sediment" (chloride oxide) and "chloride ash" also known as mercury resin, or "chloride oxide". Plister placed the oxide in the glass clock on the surface of the silver with a diameter of 30 cm and a focus of 50 cm of the lens, and concentrated the sunlight on the oxide. Soon it was discovered that the oxide was dissolved, released a gas, and the silver was ejected out of the glass mask. He called this gas "

The laboratory must be good at discovery, otherwise the experiment will be more and more in vain!