March 12 is William Perkin’s birthday. Perkin was an English chemistry student who made an accidental discovery during his homework that founded a major industry.
When coal is heated enough to form a gas and then condensed, it forms what is known as coal tar. Coal tar holds many organic molecules such as benzene and toluene and naphthalene and anthracene. These molecules form the basis of many other molecules in organic chemistry.
At 18 years old, Perkins was a student in the laboratory of German chemist August Wilhelm von Hofmann. Hofman had assigned Perkins the task of trying to find an artificial method of synthesizing the antimalarial drug, quinine. Perkins worked tirelessly on the project, even to the point of working on it at his home laboratory. During the Easter break in 1859, he was working with the coal tar derivative aniline. He added potassium dichromate to oxidize the aniline and the reaction formed a black solid implying another failed experiment. While washing out the test tube with alcohol, he noticed some of the solid turned a vivid purple color. He felt he found something interesting, but it wasn’t quinine, which his professor wanted. He continued to work on his purple chemical on his own time. He discovered the color worked as a dye after he treated a piece of silk. The silk retained the purple color even after frequent washings and exposure to light.
Perkins knew he had something special. Normally, dyes for fabric come from expensive and difficult to obtain natural products. He found something he could accomplish the same thing with inexpensive coal by-products. Using capital from his father and partnership with his brother, he created the artificial dye industry. It did not take long to make Perkins a wealthy young man.
After a few years, he left the business part of the industry to return to chemical research. He developed other dye colors and found a way to create cinnamic acid, a common carboxylic acid found in many plants. He also synthesized the first artificial perfume which revolutionized that industry as well. He would go on to join the Royal Society and win both the Royal Medal and Davy Medal. The American Society of Chemical Industry created a medal known as the Perkin Medal to go to “innovation in applied chemistry resulting in outstanding commercial development.”
Fun Fact: The first Perkins Medal went to Perkins himself.
Notable Science History Events for March 12
1991 – Ragnar Arthur Granit died.
Granit was a Swedish physiologist who shares the 1967 Nobel Prize in Medicine with George Wald and Haldan Hartline for their study of the internal electrical and chemical changes in the eye when exposed to light. Granit proposed a dominator-modulator theory of color vision where the three types of color receptors respond to certain bands of the spectrum and the other nerve fibers are responsive to narrow bands of the spectrum.
1942 – William Henry Bragg died.
Bragg was a British physicist who shared the 1915 Nobel Prize in Physics with his son, William Lawrence Bragg for the development of x-ray crystallography. They invented the x-ray spectrometer. They used their device to record the x-ray spectra of several elements.
He also worked on a detection system against German U-boats during World War I.
1925 – Leo Esaki was born.
Esaki is a Japanese physicist who was awarded the 1973 Nobel Prize in Physics with Ivar Giaeverand Brian Josephson for the discovery of electron tunnelling. He also invented the tunneling diode, also known as the Esaki diode, which exploits the tunneling effect.
Electron tunnelling is a phenomenon where electrons are found in places where under classical mechanics, they could not be found. The electron’s wavefunction can be expressed to show the electron ‘tunnelling’ through potential barriers to wind up on the wrong side of the barrier.
1924 – Hilaire de Chardonnet died.
Chardonnet was the French chemist who developed the first artificial silk substitute. He was working with Louis Pasteur when the French silk industry suffered an epidemic affecting their silkworms. An accidental spill gave him a solution. He spilled a bottle of nitrocellulose on his workbench and found evaporation caused it to become viscous. While cleaning it up, he found the mess pulled away in fibers.
He pulped up mulberry leaves with nitric and sulfuric acid to form his artificial silk, or what would become known by the name rayon.
His early form of rayon was extremely flammable (it was basically guncotton). He solved this problem by adding ammonium sulfide.
1914 – George Westinghouse Jr. died.
Westinghouse was an American inventor/entrepreneur who competed directly with Thomas Edison over the development of America’s electrical system. Westinghouse already had interests in gas and telephone service distribution. He believed his experience could be applied to the upcoming need for electrical distribution. Edison’s distribution system involved the transmission of electricity by direct current. The drawback of this is the energy loss over distance. Unless the customer is nearby, most of the generated electricity is lost to heat. Westinghouse championed the alternating current method. Alternating current can be passed through transformers to alter the voltage and current where transmission losses are greatly reduced. This is the method electricity is transported today.
Westinghouse is also known for his invention of the air brake for trains. Before this invention, in order to stop a train, linemen had to go from car to car to apply brakes manually. After witnessing a wreck where they train was not stopped in time, he developed a means to channel compressed air to each car’s brakes to engage them all simultaneously. This invention is the basis for the braking system used by trains and large trucks in use today.
1898 – Johann Jakob Balmer died.
Balmer was a Swiss mathematician best known for his development of a formula to determine the wavelengths of hydrogen spectral lines. His formula was based on measured wavelengths and it wasn’t understood why his formula worked until after his death and Niels Bohr presented his model of atomic structure.
The visible spectra of hydrogen are called Balmer lines in honor of his work.
1863 – Vladimir Ivanovich Vernadsky was born.
Vernadsky was a Russian geologist who was one of the founders of the study of geochemistry. He studied the elemental distribution of the Earth’s crust and electrical and magnetic, thermal, and optical properties of crystals. He was also known for popularizing the idea of the noosphere, or sphere of human thought. He noted the great effect humans have on the geology of their environment and included this in a wider understanding of biospheres.
1838 – William Henry Perkin was born.
1824 – Gustav Robert Kirchhoff was born.
Kirchhoff was a German physicist known for his contributions to spectroscopy and electrical circuits. His spectroscopy law deals with blackbody radiation given off when an object is heated. He discovered cesium and rubidium with Robert Bunsen using his spectroscope. His voltage laws deal with current loops (current in = current out) and voltage drops (all voltage drops in a circuit must equal all voltages applied to the circuit).
For more about Kirchhoff, check out October 17 in Science History.
1790 – John Frederic Daniell was born.
Daniell was a British chemist and meteorologist who invented the Daniell cell, which was a large improvement over the voltaic pile batteries of the time. The Daniell cell uses central zinc anode in a porous pot of zinc sulfate solution which is placed in another copper pot containing a solution of copper sulfate which acts as the cathode of the battery.
Daniel also invented the dew-point hydrometer used to measure the moisture content in the air.