Spit or swallow? What's the best way to deal with phlegm?

Spit or swallow? What's the best way to deal with phlegm?

In 1821, French physician René Laennec wrote, "A spitting pot I consider as an essential part of the bedroom apparatus." Laennec, who invented the stethoscope, spent his days gazing at his patients' phlegm. In the days before X-rays and blood tests, phlegm was considered a valuable diagnostic tool.