Chemistry

The emergence of the chemical industry was triggered by the mechanisation of English textile production in the second half of the 18th century. The output of the new spinning and weaving machines increased rapidly, and manufacturers needed new chemicals to clean and bleach the vast quantities of linen and cotton fabrics. Three substances rose to prominence: sulphuric acid, soda and chlorine. However, their closely related production processes caused serious damage to nature and human health.

Traditionally, sulphur was leached from shale and burned to produce sulphuric acid: the acid vapours were collected in vessels with water and distilled. In 1746, the English entrepreneur John Roebuck introduced lead chambers to collect the vapours. Production could now easily be increased by enlarging the chambers, and sulphuric acid became the first industrial chemical. Factories supplied acid mainly for pickling metals until demand exploded for bleaching linen and cotton. By the beginning of the 19th century, the first continuous manufacturing process was in place - a prerequisite for large-scale industrial chemical production.

Soda, chemically "sodium carbonate", was also used for bleaching, but was also a basic material for the production of glass and soap, which was also needed for textile processing. For a long time it was produced according to a principle patented by the French chemist Nicolas Leblanc in 1791: sulphuric acid and salt were heated in a furnace, the resulting "salt cake" was roasted together with lime and coal, and the water-soluble soda was then washed out of the "black ash". The process made cotton goods and glass much cheaper, but released many highly toxic by-products.

Chlorine also became an industrial product early on, thanks to its ability to bleach textiles - including rags used in paper production. The first effective bleaching agent was produced by a French factory in 1789: chlorine was added to a lye of potassium carbonate to produce "chlorine water". A few years later, the Scottish chemist Charles Macintosh discovered that chlorine gas was absorbed by slaked lime: This made a bleaching powder available - practical for industrial use, but extremely harmful to health in production.

Since its discovery in 1709, coke has been used in the iron industry for its high calorific value - and at the turn of the 19th century, a by-product of coking gave rise to a new branch of chemistry: coal gas. From 1807, gas lighting became widespread in England. First in textile mills, which produced gas on site from coal, then for street lighting: cities built huge cylindrical gas tanks in central gas works, from which "town gas" was distributed through cast-iron pipe networks. Later, long-distance pipelines from coal-rich regions were also used.

In the second half of the 19th century, during the "second industrial revolution", chemistry became the leading industrial sector alongside electrical engineering. One reason for this was that researchers were able to identify active ingredients with increasing precision. As early as the 1840s, John Bennet Lawes in England and Justus Liebig in Germany had identified the substances on which plant growth depended: Once nitrogen, potassium salt and phosphorus had been identified, it was possible to increase agricultural yields with artificially produced substances - and for the first time in history to establish secure food production independent of the weather.

On the other hand, theorists had gained insights into the structure of chemical elements: The "structural formula" developed by Friedrich August Kekulé - the most famous example being the benzene ring - made it possible to describe the composition of countless chemical compounds, thus simplifying their artificial production, or "synthesis". Chemistry took on a new face. From now on, science played a central role, as analyses were mostly carried out in university laboratories before the rapidly expanding industry could synthesise the active ingredients.

Now a second by-product of coal coking came into play: Researchers identified active substances in coal tar that could be used to synthesise dyes and, soon, medicines. In 1856, the Briton William Henry Perkin produced violet from the aniline extracted from the tar. Soon after, artificial indigo blue was made, also from aniline, and then red from madder, the root of dyeing red, was replaced by alizarin. These two dyes were developed by the Badische Anilin- und Soda-Fabrik (BASF), one of the three German chemical companies founded in the 1860s, along with Hoechst and Bayer, which overtook the English companies as the world's leading tar-dye-based corporations.