Sulphur-fume-acidulated water (dilute mineral acid)
The “active” substance in Wm. Radam’s Microbe Killer was not a drug but treated water. Radam’s own patent for the manufacturing apparatus (US 412,664, 1889) describes impregnating water with “the fumes emanating from the consumption of a combustible composition of matter, such as sulphur,” in a brick-and-cement tank lined with glass and slate and fitted with wooden faucets, because metal would be eaten by “the acids generated in using the apparatus.” The process imparts “a sour acid taste to the liquid in from four to twenty-four hours, according to the strength I desire to attain.” In his 1890 book Radam described the result as “pure water, permeated with gases.”
What this produces is a very dilute solution of sulphurous and sulphuric acid in water, lightly tinted (Barnett reports a little wine was added for a pink cast). The chemist and pharmacist R.G. Eccles analysed the Microbe Killer and reported it to be water with only minute quantities of hydrochloric and sulphuric acid; an analysis attributed to the US Department of Agriculture, as later recounted by Barnett, put the water content at 99.381 percent. The claimed mechanism, that this liquid kills the microbes that cause all disease, fails on basic grounds: an acid weak enough to be drunk by the glassful, including by infants, is far too weak to act as a systemic germicide, and swallowed acid is neutralized in the digestive tract rather than carried through the bloodstream to destroy micro-organisms in the tissues. The ingredient is recorded here as the surrogate-mechanism material at the centre of the case, a near-inert acidulated water sold as a universal antiseptic.