Congo red was introduced in 1883 by Paul Bottiger in Germany. He was looking for textile dyes, and the company Friedrich Bayer Company didn't were interested on a bright red color so filled the patent and sold it to the company under his name. The company later on market as Congo red (a catchy name at the time). The dye had became the success for the company and in the following years they continued using the "Congo" name for different dyes. In 1885 the Europeans, the word "Congo" was known as The Dark Continent. Congo was introduced in 1885 in Berlin as economically lucrative and textile dyes. Its design was introduced primary for sources consulate extensively also 19th century legal briefs, and scientific papers.
“Acid strength is measured by the pH scale, with lower numbers being stronger, and in 2005 a chemist from New Zealand invented a boron-based acid called a carborane, with a pH of -18”
― Sam Kean, The Disappearing Spoon: And Other True Tales of Madness, Love, and the History of the World from the Periodic Table of the Elements
The Congo indicates the p[H] which was introduced by Danish chemist Soren Peder Lauritz Sorensen in 1909 and checked the modern pH in 1924. The meaning of pH is because of the Carlsberg Foundation meaning for power of hydrogen. And on many other languages for example Latin, French and German their word power begins with "p".
Now in days its used by: a laboratory test used in the diagnosis of amyloidosis,measuring the amount of injected dye that is removed by amyloid in the tissues of the human patient.