July 4, 1832: Date of letter from Chester Averill (Professor of Chemistry, Union College) to the Mayor of Schenectady, New York during the middle of a cholera epidemic which praised the disinfecting properties of chloride of lime (chlorine). The treatise quoted many learned men of the time who demonstrated that chloride of lime eliminated the spread of contagious diseases by attacking the miasmas associated with them. The letter also made reference to the destruction of certain “viruses” that may have been responsible for transmission of the diseases. The germ theory of disease would not be espoused by Louis Pasteur for another 30-40 years. However, Averill, like many others in the early 19th century suspected that something other than “bad air” caused disease. What follows is a small extract from his treatise.
“‘Chlorine is by far the most powerful agent hitherto discovered to counteract contagion and all kinds of noxious effluvia and its sanative powers appear equally extraordinary.’ Dr. Sillimaii’s Chem. vol. 2, p. 68.
I have here quoted the opinions of eminently scientific men, at least three of whom are M.D.’s. and all of whom, it may be thought, do not deserve to be styled empyrics. But what weight ought these opinions to have in this discussion? Surely no more than those of any other person even much less eminent, unless they are better substantiated by facts. It was thought advisable, however, to quote them, since they may serve to correct any bias which entirely opposite opinions, proceeding from no higher source, may have occasioned.”
Reference: Averill, Chester. Facts Regarding the Disinfecting Powers of Chlorine: With an Explanation of the Mode in Which it Operates and with Directions How it Should be Applied for Disinfecting Purposes. Letter to John I. DeGraff, Mayor of Schenectady. Private printing. 1832.
Commentary: In today’s New York Times (July 4, 2013), there was an extraordinary article that summarized recent research findings on human genetic adaptation to killer cholera. A few quotes give a summary of the findings:
“People living in the Ganges Delta, where cholera is an ancient, endemic and often lethal disease, have adapted genetically to the scourge through variations in about 300 genes, say researchers who have scanned their genomes for the fingerprints of evolution.
The researchers also found unexpected changes in genes that protect against arsenic, suggesting that arsenic exposure in Bangladesh is not just a modern problem associated with deep tube wells but may have ancient roots.
These instances of natural selection probably took place within the last 5,000 to 30,000 years, the researchers say, and show how evolution has continued to mold human populations through the relatively recent past…. People with blood group O are particularly susceptible to cholera, and indeed few Bengalis have blood group O. John Mekalanos, a cholera expert at the Harvard Medical School, said the new finding was one of several that ‘are starting to give a strong impression that the human genome has been dramatically shaped by responses to microorganisms.’”
Reference: Wade, Nicholas. 2013. “Gene Sleuths Find How Some Naturally Resist Cholera.” New York Times. July 4, 2013.