The science of halitosis has come pretty far since the Civil War

The Civil War gave the U.S. a number of cultural institutions that survive today. Embalming was not widespread before the conflict, but the need to ship bodies home made it essential for the first time. The term "red tape," meaning bureaucratic paperwork, became popular, although it had been used before then. However, one thing the Civil War did not improve was knowledge of halitosis.

Consider an 1868 book called Health and Disease, a medical text published in New York City. Author William Whitty Hall wrote that bad breath is caused by stagnant blood in the veins.

"Nor is it any wonder it should be 'bad,'" he said, "when going in as pure as the breath of heaven...[it] is pushed out of the body as being too foul for any use." Hall added that "'bad' taste in the mouth of mornings is another result" of poor circulation.

Today, we know that this notion could hardly be further from the truth. Almost all halitosis, including the morning breath to which Hall refers, is caused by anaerobic bacteria, which colonize the tongue and palate, and excrete foul-smelling volatile sulfur compounds.

Rather than being concerned with one's blood, using a specialty breath freshener and brushing regularly may do the trick.