This science gave birth to a broad range of industries, some of which also poisoned people. The Leblanc process, invented by eighteenth-century French surgeon Nicolas Leblanc, treated salt with sulfuric acid to produce sodium carbonate.* Along the way, it also gave off hydrogen chloride fumes and calcium sulphide. The calcium sulphide released the classic "rotten egg" smell of sulfur to add to the black clouds and cinder of industrial centers. Hydrogen chloride fumes were worse.
The gas from these manufactories is of such a deleterious nature as to blight anything within its influences, and is alike baneful to health and property. The herbage in the fields in their vicinity is scorched, the gardens yield neither fruit nor vegetables; many flourishing trees have lately become rotten naked sticks. Cattle and poultry droop and pine away. It tarnishes the furniture in our houses, and when we are exposed to it, which is frequent occurrence, we are afflicted with coughs and pains in the head.Yikes.
- hearings at the town council of Newcastle upon Tyne, January 9, 1839
*Anon points out the obviously correct, that treating salt with sulfuric acid does not make sodium carbonate, but sodium sulfate. It appears that Mr. Kurlansky gave a somewhat incomplete description of the Leblanc process, with the missing intermediate step of treating the sodium sulfate with coal and calcium carbonate.)