Introduction
Wars have been fought since ancient times. Not long ago, armies fought face to face on the battlefield on a plain far away from inhabited areas. Throughout time, man has attempted to invent new weapons that would allow him to subdue his neighbour. However, in modern times, these weapons have become as devastating to civilians in cities as to soldiers on the battlefield. Should scientists and engineers be involved in the production of weapons of mass destruction?

In the 1850s during the Crimean War, in which Britain, Turkey and France were at war with Russia, Michael Faraday (1791-1867; Fig. 1) was asked by the British government if it was possible to prepare large quantities of poisonous gas for use on the battlefield, and if he would be interested in heading the project. Faraday is said to have immediately answered that the project was certainly feasible, but that he himself would have absolutely nothing to do with it. It was known that the French army had used poisonous gas in its colonial campaign in Algeria in 1845 and in Morocco in 1862. The issue was discussed at an international conference in Brussels in 1874 after the German-French war of 1870-1871, however, no agreement was reached. Finally, at the Peace conferences in the Hague in 1899 and 1907, chemical weapons were prohibited by the Convention of October 18, 1907 signed by Germany, France, England, Russia, and fourteen other countries. Two historic cases will illustrate the use of weapons of mass destruction: the use of poisonous gas in World War I and atomic bombs in World War II. Fortunately, research on bacteriological weapons developed during World War II was never applied.

Fig. 1. Michael Faraday (1791-1867).

Poisonous Gas in World War I
At the beginning of World War I, it was realized in Germany that there were not enough raw materials to sustain the necessary supply of munitions. Fritz Haber (1868-1934; Fig. 2), then director of the Kaiser Wilhelm Institut für Physikalische Chemie und Elektrochemie in Berlin-Dahlem, suggested the use of chlorine gas as a weapon. Officers of the Imperial Army rejected the idea, however, on Haber's insistence, a field test was agreed upon. Haber was, at that time, an influential chemist and recipient of a Nobel Prize - he had invented the ammonia synthesis process from which nitric acid and explosives could be manufactured on a large scale.

Fig. 2. Fritz Haber (1868-1934) was an advocate for the use of poisonous gas in warfare.

A portion of the Ypres front in Belgium was cleared by German soldiers. Haber then came with 5000 steel canisters filled with chlorine gas. On April 22, 1915 at 5 p.m., when the wind was blowing in the direction of Belgium, the valves of the canisters were opened and chlorine rapidly diffused in the direction of the French soldiers. About 160 t of chlorine were released along a 7 km front. Being two and half times heavier than air, the gas settled in the trenches. Casualties were enormous: 5000 died and 10 000 were paralyzed. Exposure to 0.5% concentration of chlorine in the air is enough to kill a person instantly, however, exposure to 0.01% concentration for an hour will also lead to death.

Otto Hahn (1879-1968), the future Nobel Prize winner, participated in this effort (Hahn, 1979). Figure 3 shows him in Berlin holding a gas mask and discussing with colleagues means to improve it. He was also assigned the testing of gas cylinders on the front (Fig. 4). Phosgene, COCl2, was also used by the Germans on December 19, 1915 Ypres while mustard gas, dichlorodiethyl sulphide, Cl(CH2)2S(CH2)2Cl, was used for the first time on July 12, 1917, again in Ypres. During the war, the German chemical company, I.G. Farben, produced 1000 tons/month of mustard gas. Incidentally, mustard gas is not a gas but a heavy liquid with a b.p. of 217 C. It becomes gas when applied in a bomb.

Fig. 3. Otto Hahn (1879-1968), centre, with physicist James Franck (1882-1964), left, winner of the Nobel Prize for physics in 1925 (Hahn, 1979).

When Haber wanted to proceed with another experiment on the Eastern front, his first wife, Clara, a chemist, was against the idea. When, however, Haber insisted that it was his duty to help Germany in whatever way he could, she committed suicide (Stolzenberg, 1994). During this period, Haber's institute became a war institute in which approximately 150 scientists and 2000 assistants, organized in ten groups, were active (Henning and Kazemi, 1993). Among these were:

Richard Willstätter (1872-1942) - Head of the organic chemistry department and at the same time a professor at the University of Berlin, Willstätter left his teaching position in 1912 at the Federal Technical University in Zurich to join Haber's institute. In 1916, he left for the University of Munich. He was awarded the Nobel Prize for chemistry in 1915 for his work on plant pigments especially the structure of chlorophyll. He was also the person who developed the filters found in gas masks.

Fig. 5. Hermann Staudinger (1881-1965).

Herbert Freundlich (1880-1941) - A specialist on capillary and colloidal chemistry (author of the textbook Kapillarchemie), Freundlich worked on adsorption of gases on charcoal and is best known for his gas adsorption law. He had to immigrate to England in 1933 when the National Socialist Party came to power.

Naturally, the allies also had to produce poisonous gas to use on the front. Between 1915 and 1918, about 125 000 t of gas were produced; the death toll amounted to 100 000, plus about 1.2 million injured. Fritz Haber was considered a war criminal by the Allied Forces. In spite of that, he was nominated for a Nobel Prize in 1918 which he received in 1919. Naturally, this caused a lot of controversy. The Nobel Committee, however, considered that Haber's process for ammonia synthesis was a great benefit to mankind and so he deserved the prize. After the war, when the imperial regime was dissolved, the German Reichstag ordered, in 1923, an investigation into gas warfare (Teltschik, 1992). The results were published in a report in 1927; Haber was not accused of any wrong doing. However, the discussion continued, especially by Hermann Staudinger (1881-1965; Fig. 5), who, in 1912, went to Zurich and became a professor at the Federal Technical University. He received the Nobel Prize for chemistry in 1953 for his pioneering work on macromolecules. Between 1917 and 1919, Staudinger wrote a number of articles in Revue Internationale de la Croix Rouge sharply criticizing the poisonous gas warfare. He expressed the opinion that chemistry should be used for better goals which he also presented in a number of public lectures in Zurich. He also wrote letters to his colleagues in Germany, among them Haber, condemning poisonous gas warfare.

In 1933, when the National Socialist Party came to power in Germany and the race laws came into effect, Haber had to leave in November for England. He died in exile in January 1934 while on a visit to Switzerland.

Poisonous Gas in Post World War I Era
When the war ended, peace did not ensue and the use of poisonous gas did not stop. The Russian Revolution was still going on and subduing the former Ottoman colonies was not yet complete. The British used poisonous gas on both fronts (Table 1).

Of all the belligerents in World War I, Germany had produced by far the largest quantity of war chemicals. The process of dismantling her weapons factories after her defeat, and destroying the stocks of war chemicals under the conditions of the Versailles Treaty was a lengthy one. The post-war German high command, the Reichswehr, and some individual producers of war chemicals were all seeking to hinder or delay disarmament.

Fig. 6. Bertrand Russell (1872-1970).

Spain had undertaken a colonial mission in northern Morocco that appeared to offer some compensation for the loss of the overseas colonies in 1898. However, the Army of Africa, as it was called, suffered heavy losses because it was poorly equipped, barely trained, and it lacked motivation. Immediately, when General Silvestre and his 20 000 Spaniards were defeated by the Riffians under Abdel Krim on July 21, 1921 at the battle of Anual, secret contacts were established between the Spanish and the Reichswehr. A chemical arms factory was constructed at a site near Madrid by Germans who were given Spanish nationality by King Alfonso XIII to facilitate and camouflage their mission. Later, another factory was built in Melilla in El Rif, also under the supervision of German technicians. Incidentally, General Silvestre committed suicide.

Fig. 7. Joseph Rotblat (1908-).

In the mean time, the technology of poisonous gas warfare advanced gradually. Projectiles were filled with the poisons and fired by artillery. Later, small TNT-gas bombs were dropped by the pilots from windows of low-flying aeroplanes. As the need for more sophisticated technology arose to fight the freedom fighters resisting colonial expansion, large bombs were made which could be dropped by pushing a button from a pilot's control panel. Beside mustard gas and phosgene, new poisonous chemicals were also used: chloropicrin and arsine. Balfour (2002) has recently well-documented these cases.

The way the Spanish colonial war was conducted by the king and his army resulted in dissatisfaction among the population, and a military dictatorship that deposed the king and declared a republic which lasted for five years from 1931 to 1936. This was followed by the Civil War, spearheaded by General Franco (1892-1975) who was fighting in the Riff. Strangely enough, Marshal Petain, who was French, fought alongside Franco in 1925. The Spanish Civil War ended on March 29, 1939 and World War II started on September 3 that same year.

Fig. 8. Cyrus Stephen Eaton (1883-1979).

Atomic Bombs in World War II
The dropping of atomic bombs on Hiroshima and Nagasaki toward the end of World War II in 1945, whose devastating effects are known, and the issuance of the Russell-Einstein Manifesto laid the foundation for the Pugwash conferences (Habashi, 2002). A fierce opponent of nuclear weapons, the British philosopher, mathematician and Nobel Prize winner, Bertrand Russell (1872-1970), led a sitdown protest outside the Defence Ministry in London in 1961 (Fig. 6). Russell came from an English noble family, which gained prominence during the reign of Henry VIII. The manifesto, which called on scientists to "assemble in conference to appraise the perils that have arisen as a result of the development of weapons of mass destruction, and to discuss a resolution," was signed by Bertrand Russell, Albert Einstein, and nine other noted scientists, including Joseph Rotblat (Fig. 7). Rotblat, a Polish-born physicist and a British citizen, worked on the Manhattan project in the United States but returned to England months before the first bomb hit Hiroshima because he objected to building the bomb once it became clear Nazi Germany would not develop such a weapon. Nearly 70 000 people were employed over a period of three years to produce the first two atomic bombs.

Fig. 9. Linus Pauling (1901-1994) protesting the bomb tests in front of the White House in May 1962.

The conferences take their name from the small fishing village of Pugwash, Nova Scotia, 65 km northwest of Truro at the mouth of the Pugwash River, which in 1957, hosted the first meeting attended by 22 scientists from 10 nations, including the United States and the former Soviet Union. This was followed by a series of meetings at sites around the world, with a growing number and diversity of participants. By mid 1995, there had been more than 200 Pugwash meetings with a total attendance of more than 10 000. The organization is based in London, with offices in Rome and Geneva. The U.S. Pugwash Committee is based at the American Academy of Arts & Sciences in Cambridge, Massachusetts.

Fig. 10. Andrej Sakharov (1921-1989).

The Pugwash conferences were convened by Cyrus Stephen Eaton (1883-1979; Fig. 8), a Canadian financier, multimillionaire, and philanthropist native of Pugwash. He was educated at McMaster but moved to the United States in 1900 to become involved in the steel industry, eventually forming Republic Steel. His effort to ease the Cold War between the United States and the former Soviet Union was the motive for sponsoring the Pugwash conferences. For these efforts, he received the Lenin Peace Prize in 1960.

The 1995 Nobel Prize was awarded to the Pugwash Conference on Science and World Affairs and to its president, Rotblat, to honour the efforts of an international group of scientists to influence arms control. The Norwegian Nobel Committee also emphasized the recognition of the responsibility of scientists in regards to their inventions. This Peace Prize was the fourth to be given to scientists for nuclear disarmament work, after Linus Pauling's 1962 award, Andrej Sakharov's 1975 award, and the 1985 prize of the International Physicians for the Prevention of Nuclear War Organization. Table 2 gives a summary of the peace movement.

Linus Pauling (1901-1994) was born in Portland, Oregon, studied under Sommerfeld at the University of Munich and was a professor of chemistry at the California Institute of Technology since 1927. From about 1930, he was a pioneer in the development of quantum mechanics and in its application to chemical structure and behaviour, developing the concepts of orbital hybridization and of resonance between alternative structures. In the 1950s, he made important contributions to the understanding of proteins, suggesting that they have helical structures. He also worked on the structures and properties of many other substances of biological importance. He received the 1954 Nobel Prize in chemistry and the 1962 Nobel Prize for peace.

Fig. 11. Map showing stored United States weapon-grade uranium.

Andrej Sakharov (1921-1989; Fig. 10), developer of the Soviet hydrogen bomb and Nobel Peace Prize winner in 1975, felt that the invention of this weapon was necessary because the United States already had one. However, he was horrified when he realized he had given this weapon to an irresponsible dictatorship. He wrote letters protesting Soviet atomic tests in the 1950s and 1960s. Because he was a hero of the Soviet Union, he was able to get access to Soviet leaders and make his protests personally. The leaders pretended to pay attention, but the tests continued. Sakharov protested by giving up many of his privileges, and going public with his criticism of a system that denied individuals freedom and access to information. He was exiled to Gorky for seven years until President Gorbachev announced his rehabilitation. Sakharov was elected to the new Soviet Congress and drafted a new constitution for the former Soviet Union, but soon died worn out by hunger strikes, exile, and the hard work that went into promoting freedom.

In 1994, it was revealed by the US Energy Secretary that the total production of highly enriched weapons-grade uranium in the United States was 994 t of which 259 t were stockpiled. Most of the remaining 735 t were contained in the weapons themselves (Fig. 11). Weapons grade uranium is uranium containing at least 20% uranium 235 with the remainder uranium 238, but most of that produced for weapons is at least 90% uranium 235. Naturally occurring uranium contains only 0.7% of the isotope uranium 235. A nuclear bomb can be made from about 25 kg of weapons-grade uranium.

The US Department of Energy and the Department of Defense are now in the process of deciding how much of the weapons-grade stockpile is surplus and what to do with it. Eventually, it may be mixed with uranium 238 and used for commercial nuclear power plants. The number of United States warheads, disclosed in the same report, totalled 22 229 in 1961, of which 17 187 were dismantled between 1980 and 1994. Also, the exact total number of United States nuclear weapons tests was revealed to be 1054; of these, 67 atmospheric bomb tests were conducted between 1946 and 1962 in the Marshall Islands in the Pacific. According to another 1994 report by the Russian Minister of Atomic Energy, Russia had produced 1250 t of highly enriched uranium, of which 550 t would be diluted with uranium 238 to 4.4% uranium 235. Realizing that the isotope enrichment process is one of the most tedious, slow, and expensive operations, one can only regret the wasted effort in conducting such operations. In addition, it has been recently reported that about 100 t of plutonium, originating from the dismantlement of American and Russian missiles, is being considered for use for peaceful purposes, which is not a simple matter.

Secret Canadian Research During World War II
Canadian research on weapons of mass destruction is well-documented in a Radio Canada film by Corkey and Courchesne (1999). The film also shows Canadian research in developing radar, jet fighters, and drugs to combat seasickness for the marine forces. Additional information is also given by Goodspeed (1958) in his History of the Defense Research Board of Canada. A short account is given below.

Fig. 12. John Cockcroft (1897-1967).

Atomic Research
When World War II started, British scientists were already world leaders in atomic research. In the summer of 1941, the advisory committee to the British Air Ministry headed by Nobel Prize winner George P. Thomson (1892-1975) concluded that the manufacture of atomic bombs of unprecedented destructive power was feasible. After exchanging reports with American and Canadian authorities, it was decided that no production plants should be built in Britain because of its easy access and that research should be pursued in North America. The British scientist John Cockcroft (1897-1967; Fig. 12) was appointed director of the Atomic Energy Division of Canada from 1944 to 1946 and was awarded a Nobel Prize in 1951. Before his arrival in Canada, some secret work was conducted at the University of Montreal to develop atomic weapons disguised under medical research.

Anthrax
In the summer of 1942, after conducting anthrax experiments at their germ warfare center in Porton Down, England, the British initiated a series of large anthrax bomb tests on Gruinard, an uninhabited island off the coast of Scotland. The first bomb exploded, infecting and killing about 30 test sheep in less than a week's time. Subsequent tests killed larger numbers of livestock. As might have been expected, spores eventually made their way to the Scottish mainland, causing an outbreak of anthrax. The island was so badly contaminated that it has been completely sealed off to visitors. Over the years, there have been reports that the remaining animals on the island displayed prominent manifestations of genetic change.

Canadians were only slightly behind the British with their own anthrax tests conducted on a desolate prairie town called Suffield near Calgary and Medicine Hat. Few details about these tests have ever been publicly released. Since 1942, the U.S. Army had been conducting an ongoing series of secret experiments with anthrax, often in cooperation with biological warfare scientists in the Canadian military. Canadians were producing anthrax spores at a rate of about 150 pounds per month at a secluded location on Grosse Ile, a St. Lawrence seaway island just north of Ile d'Orleans near Quebec City. Before its conversion to the bacteriological cause, the island had served as a quarantine station for immigrants wishing to enter Canada.

Fig. 13. Frederick G. Banting (1891-1941).

Surprisingly enough, the research was sponsored by the National Research Council Medical Department whose first director was the 1923 Nobel Prize winner Frederick G. Banting (1891-1941; Fig. 13), a graduate of the University of Toronto. He was famous for his isolation of insulin for the treatment of diabetics and became the pioneer researcher on chemical and bacteriological warfare. He was killed in an airplane crash.

Grosse Ile anthrax production was slow and problematic, provoking officials in the United States to decide to produce their own anthrax spores at a multimillion dollar production facility built near Vigo, Indiana, south of Terre Haute. Originally designed in 1942 by the army as a conventional munitions plant, the newly equipped plant held twelve 20 000 gallon tanks that within less than one-month's time could produce enough anthrax for 500 000 bombs. In June 1944, following the British request for a half million bombs, the United States decided to produce one million anthrax bombs, half of which would be stockpiled in the United States for possible use.

Mustard Gas
Banting also did extensive mustard gas tests on volunteers. About 2000 soldiers from Australia, India, and Canada were paid one dollar for each exposure. The results were horrifying. After the war, prime minister Mackenzie King decided to get rid of 2500 t of mustard gas in the Atlantic while the United States disposed of 10 000 t in both the Atlantic and the Pacific.

Epilogue
Poisonous gas and atomic bombs are only two examples of weapons of mass destruction. To these should also be added the large-scale assassinations conducted in Nazi Germany during World War II using hydrogen cyanide in concentration camps where millions of civilians were systematically murdered. It is also remarkable that while the poisonous gas was only used on the battlefield against soldiers in World War I, in the Spanish North African War it was used predominantly against civilians. The period between the two World Wars (1919-1939) was a period of political tension, aggressive colonial wars, and bloody civil wars.

The study of chemical and biological warfare can be traced back to 1964 when a group of microbiologists who were concerned about the problems of biological warfare started meeting under the auspices of Pugwash. It became evident that there was a need for more intense study that could be achieved through occasional gatherings of people who were busy with other work. In 1966, the Stockholm International Peace Research Institute, which was then starting up, decided to take on the task of making a major review of biological warfare. The study was soon extended to cover chemical warfare as well because it was found impossible to discuss one without the other. In 1971, the institute published its six-volume work The Problem of Chemical and Biological Warfare covering the historical, technical, military, legal, and political aspect of chemical and biological weapons, as well as possible disarmament measures, fully documented with thousands of references (Anonymous, 1971).

Not many scientists and engineers have been well educated in humanities. They are usually so involved in their professional activities that they do not have time to reflect about the problems in the society they live in. They delegate the responsibility of running a country to politicians. Some politicians may be reasonable. For example, Neville Chamberlain, the British prime minister from 1937 to 1940, declared that the bombing of civilians was unlawful. On the other hand, his contemporary British scientist, J.B.S. Haldane, openly justified the use of poisonous gas on the grounds that there was no such thing as a humane war and that chemical weapons were not different from conventional ones (Haldane, 1925). Faraday, Clara Haber, Staudinger, Rotblat, Pauling, and Sacharov are excellent examples of those mature scientists who are well conscious of their responsibilities toward society. They strongly protested the utilization of weapons of mass destruction. On the other hand, it is rather surprising that Fritz Haber and Frederick Banting, two distinguished scientists and at the same time Nobel Prize winners, create the idea of using such weapons.

References

ANONYMOUS, 1971. The Problem of Chemical and Biological Warfare, 6 Volumes. Stockholm International Peace Research Institute, Almqvist & Wiksell, Stockholm.
ANONYMOUS, 1994. Chemical & Engineering News, July 11.
BALFOUR, S., 2002. Deadly Embrace - Morocco and the Road to the Spanish Civil War. Oxford University Press, Oxford, 360 p.
CORKEY, J. and COURCHESNE, H., 1999. Histoire des sciences au Canada, Part 3: La vie et la mort - la science au service de la guerre. VHS tape, Société Radio-Canada, 49 minutes.
GOODSPEED, D., 1958. A History of the Defense Research Board of Canada. The Queen's Printer, Ottawa.
HABASHI, F., 2002. From Alchemy to Atomic Bombs. Métallurgie Extractive, Québec/Laval University Bookstore "Zone," Quebec City, p. 295-338.
HAHN, D., 1979. Otto Hahn, Begründer des Atomzeitalters. List Verlag, Munich, Germany.
HALDANE, J.B.S., 1925. Callinicus: A Defense of Chemical Warfare. Kegan Paul, London.
HENNING, E. and KAZEMI, M., 1993. Max-Planck-Gesellschaft Berichte und Mitteilungen. 3/93-Dahlem-Domäne Der Wissenschaft, Berlin, p. 69-86.
STOLZENBERG, D., 1994. Fritz Haber: Chemiker, Nobelpreis-träger, Deutscher Jude. WILEY-VCH, Weinheim, Germany, p. 223-330.
TELTSCHIK, W., 1992. Geschichte der deutschen Großchemie. VCH Verlagsgesellschaft, Weinheim, Germany, p. 43-58 and 85-87.