Today, the diagnosis of bad breath can be quite scientific. Dentists and periodontists may detect halitosis by having patients breathe into a halimeter, which is a device for measuring odorous compounds in the air of the mouth and lungs. Likewise, specialty breath fresheners now exist to eliminate precisely these odors.
However, this has not always been the case. Before 1875 or so, the study of bad breath was eccentric and irregular, and its treatments could be quite unusual.
The 1800s were a time of expanding scientific thought, when many common medical ideas were debunked in favor of more logical explanations. "Humors" became bacteria and viruses. "Consumption" became tuberculosis. And in 1874, bad breath became "halitosis," a term coined by Joseph Howe, a surgeon at new York's Bellevue Hospital.
Before that year, descriptions of bad breath could vary wildly from expert to expert.
In an 1849 book titled A Domestic Homoeopathy, physicians and authors Edward Chepmell and Samuel Barlow got fairly close to the currently accepted causes of bad breath. Fetid breath, they said, is caused by improper "attention to the mouth and teeth" or "putrid inflammation of the mouth and gums." Tooth decay and gingivitis do cause halitosis, in fact.
What was their solution? Applying alternating dabs of mercury and sulfur to the gums for four straight days.
It should be noted that ingesting mercury can cause permanent psychosis.
Samuel Fitch's 1856 manual, Six Discourses on the Functions of the Lungs, had different ideas about what causes bad breath. In a section titled "Discourse to Gentlemen Only," Fitch warned that "bad breath is almost always present in people of a costive habit." He suggested that men "solicit an evacuation" at the same time every day to eliminate the problem.
Though no longer in general use, the word "costive" is a gentler way to say "constipated."
For ladies, Fitch mentioned that people with acidic stomachs often have bad breath, as well as those with lung and sinus infections. Most health authorities today do agree that sinusitis, post-nasal drip and lung infections can leave a bad odor on the breath.
It wasn't until 1874, though that Joseph Howe coined the word "halitosis." Yet even his theories have not all stood up to inquiry. Agents of bad breath like antimony or "mercury abuse" are usually not mentioned anymore in connection to the breath anymore.
Today, the elimination of sulfuric compounds in the mouth is widely considered an effective way to improve breath. By brushing often and using a specialty breath freshening product, individuals with halitosis may get rid of odor safely and easily.