Ray Crist

Ray Crist 1996

Ray Henry Crist (born March 8, 1900 in Mechanicsburg , Pennsylvania , † July 23, 2005 in Carlisle ) was an American chemist .

childhood

Ray Crist 1905

Crist grew up in a small town in Cumberland County, Pennsylvania, on his father's forty- acre farm. He helped his father with the daily work in agriculture , and through this regular occupation with animals and plants his interest in the natural sciences developed early .

When he was four, his parents sent him to Little Grantham School, a simple village school with a single room where his aunt taught. After seven years he and his older brother Guy moved to the larger Messiah Bible School in Grantham . In 1915 he also joined the Shepherdstown United Brethren Church (now United Methodist).

At the University

A year later he graduated from high school, whereupon the 16-year-old went to Dickinson College in Carlisle. He also made progress in his church career, since he was elected curator in 1918 . Although he was now commuting between his home and university on the Dillsburg train, he continued to take time several times a week to walk two miles to Shepherdstown to attend church services and Bible studies . After he graduated with a Bachelor of Arts degree in chemistry in 1920 , the director pointed out a vacancy in the science department of Williamsport Dickinson Seminary, now Lycoming College . Thanks to a recommendation he made, Crist got this job.

In comparison to the village in which he had spent his childhood, Williamsport was a true metropolis. But Crist quickly made friends with the new reality, taught the students chemistry, biology, and physics, and found spiritual support at Mulberry Street Methodist Church. However, his calling for scientific experimentation could not be sufficiently satisfied in Williamsport.

In search of better options, he struck gold at Columbia University in New York City . Crist quickly rose to the position of research assistant and, together with John Livingston Rutgers Morgan (1872–1935), studied how salts decompose photochemically under different conditions. The main focus was on potassium peroxodisulfate (K ₂ S ₂ O ₈ ), which was also the basis for his later doctoral thesis. His first own research work in 1924 dealt with photochemical reactions of halides of alkali metals in acetophenones . It appeared in the Journal of the American Chemical Society . After his doctorate in 1926 as Doctor of Philosophy with Morgan ( The photochemical decomposition of potassium persulphate ) he was allowed to teach as a professor at the chemical institute of the university. A year earlier he had led his girlfriend Dorothy Lenhart to the altar.

In 1928, Crist was given the opportunity to go to Berlin for a year to continue his research. Here he worked with Max Bodenstein , the founder of chemical kinetics , at the Kaiser Wilhelm Institute for Physical Chemistry and Electrochemistry .

Back at Columbia University, he mainly lectured on photochemistry . Harold Urey , also a professor, who discovered deuterium in 1931 and was awarded the Nobel Prize for Chemistry three years later, attended his first lecture . In the ranks of his students in the first semester there was also George Wald , who was awarded the Nobel Prize in Physiology or Medicine in 1967.

In addition to photochemistry, the focus of his research was on kinetic reactions of gases . He was also associate editor of the Journal of Chemical Physics and wrote a general textbook on experimentation in the chemistry laboratory.

The Manhattan Project and Atomic Research

Crist worked with Urey on various projects in the 1930s. Shortly after the discovery of nuclear fission , the Nobel Prize laureate was informed of the plans that were to lead to the development of a US atomic bomb . Therefore, in the summer of 1940, he had Crist determine the vapor pressure and triple point of uranium hexafluoride (UF ₆ ). This compound was later used to separate the fissile isotope uranium- 235 from uranium-238 using gas diffusion processes.

At the beginning of the Manhattan Project in 1941, under which the development of the atomic bomb was traded, Urey rose to the director of the Columbia University projects department, while Crist became his assistant. He headed the department that worked on the large-scale separation of deuterium from hydrogen . They wanted to use the heavy hydrogen to control the speed of neutrons and thus maintain a nuclear chain reaction over a long period of time. Crist later led research on the separation of uranium isotopes , using a porous nickel alloy as a diffusion barrier . After the most important development goals had been achieved in 1945, he took over the post of director in Urey's place and led the university's atomic research until it ended the following year.

During this time Albert Einstein was also one of Crist's circle of friends.

Work in the private sector

Towards the end of the war it was clear that the number of government-sponsored projects at Columbia University would be drastically reduced. Crist could have stayed as a professor, but the chemist who was used to country life disliked life in the big city. In particular, he no longer wanted to expose his three young sons, the twins Henry and DeLanson and the adopted Robert, to New York. He also did not take up the offer to join the new research institute at the University of Chicago and work with Urey, Fermi and other former employees of the Manhattan Project and instead went into the private sector: in 1946 he moved with his family to Charleston in West Virginia to earn his living as director of research at Union Carbide Chemical Corporation , one of the main government contractors during World War II .

His most important project in this position was an attempt to hydrogenation of coal to these takes natural gas as raw material for carbide business with aliphatic to use connections. Under his direction, a system was developed that could deliver three hundred tons of it a day and was in use for twelve years. However, the discovery of large oil fields in Saudi Arabia lowered oil prices , causing Carbide to terminate their project.

Therefore, Crist moved to Tarrytown (New York) in 1959 and became director of the new Carbide Research Institute, which carried out basic research for all other departments, u. a. on the hydrocarbon olefin .

Return to the university

After he voluntarily gave up this position in 1963, however, he was not yet ready to stop working entirely. His wife had died of a heart attack the year before. He returned to Dickinson College and received a visiting professorship there.

Affected by the rapid development of science and its growing influence on society, industry and, above all, the environment , he saw it as his duty to impart knowledge about the correct and controlled use of technology to the younger generation. His interest was in the humanities students, for whom the natural sciences were only minor subjects. Crist thought her natural history training was inadequate. He therefore supervised student projects in the field of environmental chemistry and gave chemistry classes to freshmen. He also set up a course on the history of science. C&EN took up some of his training ideas in an article in 1964.

In 1971 the university duly retired him. But Crist was far from thinking of quitting and went back to his very first place of work in Grantham, which had meanwhile become the humanities Messiah College . For the symbolic payment of a dollar a year, he worked forty hours a week for 33 years. Initially, he taught the students and helped develop the university program in environmental science. He later stopped teaching, but continued to work with the students on research projects. For the past few years, he has done research mostly alone in his laboratory in the Klein Science Center on campus.

During this time, Crist played the role that cadmium plays in raising blood pressure in rats , lead , which displaces copper and zinc from the enzymes in a rat brain, the formation of nitrogen oxides from ammonium nitrate fertilizers in the soil, which destroy the ozone in the upper Atmosphere , the rate of proton transport through the cell membranes of red blood cells and the copper uptake of algae are investigated.

The study of the algae developed into an ongoing program that examined the chemical mechanisms behind so-called biosorbents - u. a. Algae, peat moss and plant roots stand when they absorb metal ions . These surface chemical investigations led Crist and his colleagues in 1981 to the result that when algae absorb metal, protons are simultaneously released and the pH value is lowered. Protons, which are associated with the numerous acidic functional groups in living plant and animal tissue , can easily be exchanged for metal ions, according to Crist. Before, metal uptake was thought to be a simple adsorption process .

In doing so, he made a special contribution to environmental protection . The algae can help rid the water and soil of toxic, contaminating metals. This ability of organic material to remove pollutants is subsumed under the term bioremediation .

Crist received 150 reprint requests for the scientific documents that resulted in the study. The work has resulted in a total of 27 publications during his last twenty-five years of apprenticeship - that's about half of all publications in his entire career. Since 1990 the results have been published in eleven international newspapers, including the renowned Journal of the Pennsylvania Academy of Science . They have also been presented at numerous conferences at home ( Chicago , California , Atlanta and Florida ) and abroad ( Montana , Sweden , Japan and France ).

The age record holder

Towards the end of the 20th century, Crist turned his attention to the polymer lignin , which gives the cell walls of wood plants their strength. It remains as a by-product in the wood pulp in the manufacture of paper . He saw it as a possible medium for inexpensive bioremediation. By mixing lignin with dimethylformamide and adding heat to the resulting product to remove the remaining solvent, Crist developed lignin-based plastic chips. This porous and dry material is able to absorb metals such as lead and cadmium. In November 2001, Crist and Messiah College applied for a provisional patent on the process. In early 2002, his findings on the absorption of metal ions by lignin appeared in Environmental Science & Technology .

In September of the same year, the non-profit Experience Works honored him as the oldest active worker in the United States. Although his eyesight has decreased significantly in recent years due to retinal degeneration, so that he could only see weakly in the left eye and he needed a pacemaker and a hearing aid , he did not retire until April 14, 2004, at the age of 104 . This long working life was made possible in particular by the active support of his colleagues, including J. Robert Martin. In total, he can look back on over 50 academic papers.

In 2005 his memoir Listening to Nature: My Century in Science was published , which he wrote with the help of his son Robert. He died after a stroke on July 23, 2005 in Carlisle.

His three sons also made careers in the scientific field: Robert L. Crist became professor of English literature at the University of Athens , Henry S. Crist was a pathologist at Hershey Medical Center, and DeLanson R. Crist was professor of chemistry at Georgetown University .

literature

• Ray H. Crist with Robert Crist: Listening to Nature: My Century in Science . Seaburn Books 2005, ISBN 1-59-232080-5 .
• Milton Loyer: America's Oldest Worker Started at Lycoming College. In: Lycoming College Magazine , Fall 2003, pp. 46f. ( online ; PDF; 1.4 MB)
• Stephen K. Ritter: Chemistry 102. Centenarian Ray Crist, still in the lab, is making key contributions to bioremediation research. In: Chemical & Engineering News , Vol. 80, No. 38, September 23, 2002, pp. 93-98. ( online )

Individual evidence

1. ↑ Life data, publications and academic family tree of Ray H. Crist at academictree.org, accessed on January 28, 2018.
2. ^ B. Weinstock, RH Crist: The Vapor Pressure of Uranium Hexafluoride. In: J. Chem. Phys. , 1948, 16, pp. 436-441; doi : 10.1063 / 1.1746915 .

Web links

• Dickinson College Obituary ( September 10, 2006 memento in the Internet Archive )

This version was added to the list of articles worth reading on October 7, 2005 .