Attempts to weaponize food, as in the case of tear gas, show that sometimes the most primitive of weapons can be the most effective.

FACT CHECK: We strive for accuracy and fairness. But if you see something that doesn't look right, contact us!

RELATED CONTENT

Two shipwrecked Spaniards are taken in by the Mayans and learn their way of life. One rejects it, but the other takes a more surprising path.

Ancient Mayans studied the skies thousands of years before modern astronomical observatories.

Ancient Mayan structures have lasted thousands of years, and their designs continue to influence modern architecture.

The growth of the great Mayan civilization is as much a mystery as its disappearance.

As the Cold War wore on, the American government became increasingly concerned about a potential Soviet strike on the U.S. mainland. In this footage from the early 1960's, children are used to test the effectiveness of gas masks.

In this video clip of History's Mail Call, host R. Lee Ermey takes a look at how gasmasks work and explains why those sold in surplus stores are not worth the money. Military gasmasks will save your life if they are made and worn properly. When poisonous fumes enter the mask it passes through a filter with a dense layer of carbon and thick padded air cleaner. It is then cleaned and provides fresh air to the soldier or person wearing the mask.