Tungsten evaporated crystals and 1cm3 cube (Alchemist-hp (www.pse-mendelejew.de)).

Tungsten is an incredible material. It is dense and hard, and it has the lowest vapor pressure and highest melting temperature of all metals. This combination of properties makes tungsten extremely valuable for a myriad of applications, while at the same time creates great challenges in the processing of the metal.

As a child, I was fascinated by how things work and spent a lot of time taking things apart. As with most budding engineers, I rarely reassembled them. Incandescent bulbs were one of my first quarries, carefully disassembled to reveal a hidden treasure: a tungsten filament. It was amazing that this tiny wire could be heated to white-hot temperatures to produce light.

Also at an early age, I was introduced to vacuum tubes, and to this day they are magical in my eyes. When a tungsten filament is heated in a vacuum, the electrons near the surface become energetic enough to be emitted into the surrounding space. Additional tungsten conductors, in the form of grids and plates, can be added to the bulb, and the electrons can then be manipulated to switch, rectify and amplify These electronic switches were crucial in the development of modern electronics.  

Tungsten at a Glance: Name: From the Swedish tung sten, meaning heavy stone. The symbol is from mineral wolframite, from which the element was originally isolated. Atomic mass: 183.84. History: Isolated in 1783 by Spanish chemists Juan Jose and Fausto Elhuyar. Occurrence: China has 75% of the world’s tungsten ores. Appearance: Silvery white metal. Behavior: Tungsten has the highest melting point and highest boiling point of all metals. Uses: Tungsten is used in high-temperature applications such as heating.

-Rick Lowden  

It’s Elemental: Tungsten  

Chemical & Engineering News, September 8, 2003 

X-ray structure of two copies of Zaire Ebola virus protein (green, blue) shielding viral RNA (pink).

A new molecular view sheds light on how the Ebola virus evades recognition by the immune system: It uses a cloaking mechanism to mask a telltale sign of its invasion (Nat. Struc. Mol. Biol., DOI: 10.1038/nsmb.1765). The finding could lead to treatments for Ebola hemorrhagic fever, the severe and often fatal disease that follows infection with the virus.

Ebola is a wily infectious agent for which there is no cure, explains Gaya K. Amarasinghe, a biochemist at Iowa State University. It leaves a calling card in cells upon infection: its double-stranded RNA. Usually, that RNA would trigger the human immune system. But the virus makes a protein called VP35 that masks the RNA, thereby squelching the immune response.

To learn more about how the masking works, Amarasinghe, virologist Christopher F. Basler of Mount Sinai School of Medicine, and colleagues determined the X-ray crystal structure of a double-stranded Ebola RNA bound to VP35 from the deadly Zaire species of the virus. They find that multiple copies of VP35 assemble to cloak the RNA. One copy uses a pocket of hydrophobic amino acids to recognize the RNA backbone and cap the end of the double-stranded RNA. Another copy binds to the backbone through a patch of basic amino acids. Changes to two of those basic residues are enough to destroy the virus’s disease-causing ability in guinea pigs, the team recently found (J. Virol., DOI: 10.1128/ JVI.02459-09).

-Carmen Drahl

Ebola’s Clever Cloak: Protein that hides viral RNA prevents immune system’s detection of deadly virus

Chemical & Engineering News, January 25, 2010

Rocket engine. Bruce Schmitz examines a rocket engine being developed for NASA by Rocket Research Corp. It will be designed to deliver highly reproducible thrusts for making small corrections in the speed and direction of spacecraft. The propellant will be pure hydrazine or mixtures of hydrazine, nitric acid, and water, so the propellant’s freezing point can be reduced to -20° F.

Chemical & Engineering News, January 17, 1966

Is there a limit to the size of the molecule that can be characterized directly by x-ray crystal diffraction? There is, says A. L. Patterson of the Institute for Cancer Research and the Lankenau Hospital Research Institute. With considerable struggle one can do a molecule with 25 to 50 atoms, he declares, but the boundary of practically solvable molecules is about 100 atoms.

"There is almost no doubt that continuation of x-ray diffraction work on crystals of simple proteins will lead to the elucidation of their atomic arrangements within the next few years." This side of the coin is advocated by David Harker of Brooklyn Polytechnic Institute. Such giant molecules as hemoglobin and the nucleic acid derivatives can be mapped accurately by diffraction methods, he claims. In a goodnatured disagreement during the symposium on crystal structure by diffraction, Harker told the Division of Physical and Inorganic Chemistry that full characterization of large molecules is simply a matter of time and hard work.

-Chemical & Engineering News, September 27, 1954

Turns out Harker won this argument, judging from the rich array of structures in our special issue celebrating 100 years of X-ray crystallography. You can add your favorite crystal structure to the mix here.

Hugh M. Browne’s physics class at Hampton Institute, c. 1898.

"Science experiments are talks with Nature in her own language. … The white race has been questioning Nature for centuries and has grown powerful thereby in every particular." —Hugh M. Browne,  professor of physics, Hampton Institute, Hampton, Va., 1889 

The visitor [to the exhibit “Science in American Life” at Smithsonian Institution’s National Museum of American History] encounters highlights of early efforts in the U.S. to involve minorities in the sciences. By using the methods of experimental science, Browne believed that blacks could command the same power as whites. Hampton Institute was founded in 1868 to help former slaves adjust to life as free men and women. It was a model for other schools that emphasized the practical value of science.

Browne believed that learning physics was the best way to acquire knowledge and discipline, and he made science the basis of his philosophy of racial uplift.

… “If science had been confined to academic research laboratories, it would not have had so profound an influence on society. Scientists were teachers and public servants who improved education, the food supply, public health, and sanitation. Because of their work, science became more familiar to society at large and became the basis for many technical jobs in a rapidly changing economy,” says Arthur P. Molella, chairman of the museum’s department of history of science and technology and chief curator of the exhibit.

-Linda Romaine Ross

Science in American Life

Chemical & Engineering News, March 7, 1994

The things which stand out in my memory in connection with the San Francisco meeting in 1910 are: the visit to the Petrified Forest on the way out; the wonderful purple light on the Colorado Canyon, with which we were favored by holding the train until sunset; the train wreck between Los Angeles and San Francisco and marvelous escape of the members of our company; and, most valuable of all, the friendships made during the trip.

-W.A. Noyes, Urbana, Ill., May 10, 1935

Reminiscences of American Chemical Society San Francisco 1910 Meeting

Chemical & Engineering News, June 20, 1935

This week, we’re celebrating 100 years of X-ray crystallography with a special issue full of structures that changed the world. New technology introduced in the 1960s gave the field an enormous boost, as this story from our archives shows:

Until recently, nearly all crystallography studies were based on experimental methods established during the 1920’s, although there had been a steady improvement in technique, particularly since 1945. But in the past few years, automation procedures have been applied to intrinsically superior experimental methods. This development, together with corresponding advances in computing techniques, undoubtedly portends a sharply improved flow of crystallographic information, in quality as well as in quantity. 

Each atom in a crystal has the power of scattering an x-ray beam incident on it. The sum of all the scattered waves in the crystal results in the x-ray beams diffracted from each allowed crystal plane; and the intensity of each “reflection” forms the basic information required in crystal structure analysis.    

The traditional photographic technique can be compared with the automatic diffractometer method by considering a typical series of intensity measurements. Let us assume that the average single crystal is characterized by 1000 independent reflections. Then, for a complete analysis, about 100 photographic records would be needed to measure these reflections in the popular multiple film technique. Collection of the films would take at least a month, and then each would have to be “read” by an experienced observer who estimates the intensity of each spot. These values would be placed on a common scale and averaged, and finally they would be reduced to a single collection of 1000 intensity values.

…Using an automatic diffractometer, the corresponding times depend directly on the statistical precision and overall accuracy desired. With a precision of better than 1% and an accuracy of 5 to 10%, it is easy to measure about 200 reflections in 24 hours; thus, the total measurement time is reduced to less than a week. The integrated intensities are extracted from the diffractometer output record by a high speed computer, the systematic corrections are applied, and the final set of structure factors is obtained on a common scale, all in less than half an hour of computer time.

-S.C. Abrahams

Automation in X-ray Crystallography

Chemical & Engineering News, June 3, 1963

Induction. Edmond Domboski of Pennsalt Chemicals checks an inductively heated reactor in the high-temperature laboratory. The device, seen in the foreground, is used in studying gaseous reactions at 1000° to 2000 °C. The copper coil surrounding the glass container receives radio-frequency energy, which is transferred to the graphite tube in the center of the vessel. This system eliminates the need for internal electrical connections and reduces some problems associated with experiments carried out under vacuum or in controlled atmospheres.

Chemical & Engineering News, January 17, 1966

Top, equipment used by Priestley in his experiments on gases (Wikimedia Commons). Bottom, Scheele, Mme. Lavoisier, and Priestley in “Oxygen” simulate Lavoisier’s famous experiment on oxygen’s role in respiration (courtesy of Carl Djerassi).

Today in 1774, Joseph Priestley isolated oxygen. Here are some musings on the invaluable element from scientist and playwright Carl Djerassi:

One need not be a chemist to know that without oxygen a human life would cease in seconds or minutes rather than decades. But as an organic chemist who has practiced his art for more than half a century, I must concede that without oxygen I would not have published a single paper, because most of my chemical life was spent grazing in steroid pastures. Few classes of organic molecules are as interesting as steroids—covering the gamut from sex hormones, oral contraceptives, bile acids, corticoids, vitamin D, and cardiac glycosides to anabolic drugs of abuse—yet this panoply of biological diversity is based on a single chemical template: the tetracyclic C17H28 steroid skeleton. A thin paperback written solely in two letters (C and H) becomes the steroid “Bible of Life” through addition of a third letter, O, that nature—and occasionally clever chemists—introduce into select places on that template.

… But as a chemist turned playwright, let me end with some lines from “Oxygen”—a play I wrote with Roald Hoffmann:

ASTRID: First to the discovery: No one will question that oxygen confers great benefit on mankind, right?

BENGT: Oxygen was good for people before it was “discovered!”

And then Mme. Lavoisier’s conclusion of the play: “Imagine what it means to understand what gives a leaf its color! And how it turns red. What makes a fever fall, a flame burn. Imagine!”

It’s Elemental: Oxygen

Chemical & Engineering News, September 8, 2003

Signs of life. Harvard astronomer Carl Sagan says that “had the Mariner IV vehicle passed the same distance from earth that it did from Mars … no sign of life on our planet would have been uncovered.” At bottom left is a shot of Mars from 6000 miles above its surface. At bottom right is a panoramic view of the U.S. from 430 miles above earth. Above: A Mariner spacecraft is checked out by NASA technicians. Objective of Mariner missions is to collect data in interplanetary space between earth and Mars and in the vicinity of Mars. Mariner program will run through 1969.

Search for Life on Mars Faces Delays From Squeeze on Nonessential Spending

Chemical & Engineering News, January 17, 1966

Sun-Pumped. The image of Richard J. Tarzaiski, an RCA physicist, is reflected in the parabolic mirror that collects the sun’s rays to power a sun-pumped laser. Such a device, which requires no other power, might be a communications link from a spaceship 50 million miles from the earth  (UPI Photo).

Chemical & Engineering News, January 17, 1966

Civilian Public Service worker distributes rat poison for typhus control in Gulfport, Mississippi, ca. 1945 (top, Wikimedia Commons). Thallium pieces in ampoule (bottom, W. Oelen/Wikimedia Commons).

To many people, thallium is synonymous with rat poison. It is more toxic to mammals than mercury, cadmium, and lead and has been responsible for many deliberate, accidental, occupational, and therapeutic poisonings of people since its discovery in 1861.

Public angst and concern were first drawn in the late 1960s to reports of widespread contamination of the Great Lakes’ ecosystems with toxic metals. At the time, I was a graduate student at the University of Toronto. Of the various groundbreaking studies on the hazards of heavy metals in the Great Lakes basin, I was captivated by reports that alluded to the fact that symptoms typical of thallium poisoning were being observed in many wildlife populations in the Great Lakes basin, and especially one report that claimed that nine out of the 34 bald eagles found sick or dying in 1971-72 in parts of the basin in the U.S. were poisoned by thallium.

Compared with many heavy metals, thallium has a short history and what appears to be a rosy future. Its traditional uses (in rodenticides and insecticides, pigments, wood preservatives, and ore separation; in mercury lamps to increase the intensity and spectrum of the light; as catalysts in chemical syntheses; and so forth) are being phased out in deference to its toxicity. At the same time, there is increasing demand for thallium in the high-technology and future-technology fields.

Among the growing uses for thallium are in the semiconductor and laser industry, in fiber (optical) glass, in scintillographic imaging, in superconductivity, and as a molecular probe to emulate the biological function of alkali-metal ions.

-Jerome O. Nriagu  

Chemical & Engineering News, September 8, 2003

Alexander Litvinenko (top). The high-profile Russian defector was felled by polonium-210.

In yet another oft-told tale, the book recounts the 1910 murder in England of Belle Elmore, better known as the wife of the notorious Dr. Crippen. Mrs. Crippen was a minor but popular singer in Edwardian London. Dr. Crippen was, by most standards, a con artist with problems on both sides of the Atlantic. As many stories of the infamous crime tell, Mrs. Crippen had the money and Dr. Crippen had a mistress, ensuring that their marriage would come to an unpleasant end.

The murder happened when, after a small party, Dr. Crippen, who had earlier purchased hyoscine or scopolamine from a pharmacist, apparently gave his wife a drink containing it. Instead of dying neatly, she must have required a coup de grace that made the body impossible to pass off as a natural death. Crippen disposed of the body by removing the flesh, treating it with quicklime and burying it in the basement of his house.

After the murder was discovered and the body located, Crippen and his mistress—interestingly disguised as father and son—boarded a ship for Canada. The ship’s captain recognized Crippen and radioed the authorities in London, something unusual in 1910. A faster ship with a pursuing detective chased Crippen to Canada and he was arrested there. At his trial, he was convicted of murder, and he was subsequently hanged. The trial involved the well-known pathologist Sir Bernard Spilsbury (who appears again later in the book). This case strained the limits of the known sciences of the time, including an identification of the victim from soft tissue (a recently questioned identification), the chemist’s identification of the poison, and the use of the new “wireless” for communication to alert the police.

-Reviewed by Charles S. Tumosa

Murderous Molecules: Accounts of true crimes in which victims were polished off by poison

Chemical & Engineering News, February 2, 2009

Bismuth crystal illustrating the many iridescent refraction hues of its oxide surface (Alchemist-hp + Richard Bartz / Wikimedia Commons).

Bismuth is the heaviest nonradioactive element and is essentially a nontoxic neighbor of lead and thallium in the periodic table. It is mined as bismuth oxide (Bi2O3, also known as bismite) or bismuth sulfide (Bi2S3, bismuthinite), and the brittle, silvery elemental form is one of a few substances (water is another) for which the solid is less dense than the liquid. Although bismuth has been extensively used in alloys, pharmaceuticals, electronics, cosmetics, pigments, and organic, the chemistry of bismuth is perhaps the least well established of the group-15 elements (known as the pnictogens). Compounds of bismuth typically have low solubility in most solvents, so that definitive formula assignments are usually based on X-ray diffraction studies of crystalline samples that have been isolated in small or indefinite quantities. Most isolated compounds are unique rather than members of a series of related compounds illustrating fundamental chemical trends. 

The bioutility of bismuth compounds has a 250-year history that includes numerous medicinal applications; however, the mechanisms of bioactivity are not understood. Moreover, as for most compounds of bismuth, the chemical characterization of biorelevant complexes remains incomplete. Although the “heavy metal” designation has impeded application of bismuth chemistry in medicine, two compounds have been extensively used for gastrointestinal medication for decades. Pepto-Bismol contains bismuth subsalicylate, and De-Nol contains colloidal bismuth subcitrate. The use of these compounds for the treatment of travelers’ diarrhea, non-ulcer dyspepsia, nonsteroidal anti-inflammatory drug damage, and various other digestive disorders extends from the previous use of bismuth compounds in the treatment of syphilis and tumors, in radioisotope therapies, and in the reduction of the renal toxicity of cisplatin.

-Neil Burford

It’s Elemental: Bismuth

Chemical & Engineering News, September 8, 2003

Coherent light. Bell Telephone scientists W.S. Boyle (left) and R.J. Collins prepare to fire an optical maser—microwave amplification by simulated emission of radiation—from Holmdel, N.J., to Murray Hill, N.J., 25 miles away (top photo). Heart of the maser is a synthetic ruby rod silvered at the ends. When illuminated, the rod produces a beam of coherent (single phase) light. Red flashes from the maser are picked up on a phototube (lower photo) by scientists W.L. Bond (at tube) and D.F. Nelson in Murray Hill. Message comes through in a code based on repeated flashes.

Chemical & Engineering News, October 17, 1960