COMPOSITION OF THE ATMOSPHERE

We sometimes take the air we breathe for granted. Ever since our first breathe we have continuously taken oxygen out the air, without thinking how oxygen got there. Our body creates carbon dioxide, which we exhale and that gas is added into the atmosphere. Each one of us is changing the atmosphere.

In ancient civilizations, people could not understand the origin of many substances. Wind could be gentle as it brought a cooling effect, but could be devastating in a storm. Wind seems to come from outer space, but is invisible. You can feel and hear it, but you can’t see it. Air as a mixture of gases, was not really understood until the late 1700's.

It took a few scientists to discovered the composition of air. Joseph Black in the mid 1700's discovered "fixed air," or what we call carbon dioxide. He described the gas that was released from magnesium carbonate. As he learned the properties of carbon dioxide, he could then isolate it in air. 

Earth's atmosphere

Joseph Black