A Higher Form of Killing: The Secret History of Gas and Germ Warfare

TWO The Serpent and the Flower

THE WORLD’S OLDEST chemical warfare installation occupies 7,000 gently rolling acres of countryside on the southern edge of Salisbury Plain, known as Porton Down. In 1980, over 700 men and women worked there in labs and offices scattered through 200 buildings. There were police and fire stations, a hospital, a library, a branch of Lloyds Bank, a detailed archive with thousands of reports and photographs; there was even a cinema to screen the miles of film taken during experiments. These were the residue of more than six decades of research, generally at the forefront of contemporary scientific knowledge. Though there have been many political storms, and several attempts to close it down, Porton has survived them all – proof of the military’s enduring fascination with poison gases, even in a country which now officially has no chemical weapons.

It was in January 1916 that the War Office compulsorily purchased an initial 3,000 acres of downland between the tiny villages of Porton and Idmiston, and began to clear a site for what was then known as the War Department Experimental Ground. Within two months the first scientists had arrived. At night they slept in the local inn; during the day they worked in a few ramshackle wooden huts housing a gas chamber, a laboratory and some cylinders. They were pioneers, bringing a scientific knowledge then in its infancy into a new era – and in the rush of events in the middle of the Great War seem to have been free of any ethical worries about the nature of their work. The head of the Physiology Department, Joseph Barcroft, was actually a Quaker – probably the only member of the Society of Friends ever to have had a prototype bomb named after him.¹

In the early days there was little understanding of the long-term hazards of gas, or even of how it affected the body. A complete set of experimental procedures had to be worked out from scratch – a dangerous business, and one which produced its heroes. Barcroft himself wanted to settle a dispute between the British and French about the effectiveness of hydrogen cyanide (HCN). The French had tested HCN gas on dogs, all of which died, and believed as a result that it would make an effective chemical weapon. The British conducted their tests on goats, which survived. One night Barcroft waited until everyone else had gone to bed, found a corporal to act as a witness, and without putting on a mask stepped into a gas chamber with a 1 in 2,000 concentration of hydrogen cyanide. He took a dog in with him. He recalled:

The affair of Barcroft’s Dog became one of the most famous incidents in the early history of chemical warfare. The Prime Minister, Lloyd George, wrote to Barcroft that he felt ‘the most intense admiration for the gallantry and devotion which you have shown… I desire to express personally, and as Head of His Majesty’s Government, my high appreciation of your brave action, which obtained information of quite exceptional value.’³ ‘Good God,’ said King George V when he heard of it, ‘what a wonderful plucky thing to do.’⁴

Barcroft’s phlegmatic attitude typified the early days of chemical warfare research. There were hair-raising stories. On one occasion, one of his female assistants travelled by train from his laboratory in Cambridge carrying a canister of poison gas. The canister began to leak in the compartment. She attached it to a piece of string, hung it out of the window and completed her journey to Porton.

Working methods were rough and often highly dangerous. A circular system of trenches was dug, from the centre of which cylinders of gas were discharged. Human guinea pigs (‘observers’ in Porton’s terminology) would station themselves in trenches and – for as long as they were capable of standing it – take detailed notes of the symptoms they felt. Indoors, the effects of chemicals were studied in the gas chambers. Ten minutes was found to be about the maximum most men could take exposed to a non-lethal gas. Observers were expected to stand in clouds of lethal gases for hours wearing prototype masks to test their reliability. Later, when mustard gas made its first appearance, they rolled up their sleeves and allowed their arms to be contaminated, in order to study the progression of the terrible blisters that developed. The work, wrote Foulkes (who was offered the job of Commander of Porton after the war, but turned it down) was ‘unpleasant’ and ‘dangerous’:

According to Porton’s own, recently declassified ‘in-house’ history, the demand for human beings needed in tests often far exceeded supply, ‘and cooks, orderlies and clerks were frequently pressed into service for experiments.’⁶ Foulkes himself made a point of personally being exposed to every war gas considered for adoption by the British.

Not all the early scientists survived. Colonel Watson, head of the Allies’ Central Laboratory in France, died as a result of experiments he had conducted on himself. So too, in the final days of the war, did Colonel Harrison, Deputy Controller of the British Chemical Warfare Committee. Many more must have appreciably shortened their lives by their work. ‘Risks were taken,’ runs Porton’s internal history, ‘and sufferings were endured in a manner which was only possible by men of high morale under the urge of war.’

In their investigation into the effects of gas, the scientists at Porton had other sources of information apart from the experiments they conducted on one another. In 1917 a farm and breeding colony was added to the Establishment to provide the vast numbers of animals used in experiments. Thousands of reports of experiments made in these early years have now been released to historians.⁷ They give some idea of the scale and substance of the grim research which has made Porton notorious among antivivisectionists. Cats, dogs, monkeys, baboons, goats, sheep, guinea pigs, rabbits, rats and mice were variously tethered and caged outdoors in the trench system and indoors in the gas chambers for exposure to gas clouds. Chemicals were squirted into their faces and injected into them, and bullets, sprays and bombs fired into, over and at them. With the discovery of mustard gas, bellies and backs were shaved and the chemical rubbed in; some animals were opened up and their organs smeared with mustard, the wound then stitched back together and the symptoms which developed noted. The Establishment became such a prominent centre of vivisection that it later developed its own strain of ‘Porton mice’, now a standard laboratory animal in use throughout the world.

These animal experiments were as unpopular among most non-scientists then as they are today. Haldane records that the physiologists at Porton ‘had considerable difficulty in working with a good many soldiers because the latter objected so strongly to experiments on animals, and did not conceal their contempt for the people who performed them’.⁸ And Sir Austin Anderson – at that time a junior member of Porton’s staff – recalled ‘a highly intelligent and friendly little monkey that the men loved so much that they gave him a little khaki coat with corporal’s stripes, christened him the APM, and gave him the free run of the animals’ quarters. He never went into the gas chamber and I think he survived the war.’⁹

The hours at Porton during the First World War were long, the number of experiments almost more than the system could cope with. ‘It was not uncommon for the Officer-in-Charge to spend four to six hours each evening, seven days a week, in writing up and assessing accumulated results.’¹⁰ And always, a few hundred miles away in France, was the pressure of battle, the scientists’ main source of raw data. ‘We had,’ wrote Foulkes, ‘in the theatre of war itself a vast experimental ground… Human beings provided the material for these experiments on both sides of No Man’s Land.’¹¹

The bodies and organs of gassed soldiers were regularly shipped back to Porton for microscopic examination by the physiologists of the Royal Army Medical Corps – ‘the body snatchers’ as they were known at Porton. For the scientists’ records, oil paintings were made of organs taken from post mortems. In some cases body parts themselves were preserved: a scientist’s report of October 1923, five years after the end of the war, speaks of ‘a score of human cases gassed by HS in France, which I have recently had an opportunity of studying.’¹²

As the war progressed and work intensified, Porton underwent rapid expansion. Its testing ranges were doubled in size. The early collection of huts grew into a small village, housing five separate sections. Eight rows of barracks accommodated more than a thousand troops, ballistics experts, army doctors and scientists. These were backed up by a civilian workforce of five hundred. To the system of trenches and dug-outs was added a new firing range, a mile and a half long, manned by wounded artillery men; they claimed that with their pay topped up by Porton’s ‘danger money’, they earned more carrying out test shoots on Salisbury Plain than they did under fire from the Germans on the Western Front.

The outbreak of peace in Europe in 1918 was only a minor hiccup in Porton’s routine. On Armistice night the animal keepers got drunk and released the monkeys who spread considerable alarm and confusion in the Salisbury area; apart from that it was business as usual. Professor A. E. Boycott, an ardent pacifist who had decided to work at Porton only as long as the war lasted, was one of the very few to leave: ‘the day after the Armistice he flatly refused to have anything more to do with gas warfare’.¹³

At the end of the war, Porton was not closed down. Instead, in 1919, the Government set up the Holland Committee. They unanimously recommended that Porton continue in action, and went on to lay down many of the principles upon which the Establishment is run today. In view of the ‘large degree of risk’ entailed in the work, ‘a very liberal allowance of leave’ – three months a year – was granted to the staff. Everything possible was done to attract ‘the best brains in the country’ to Porton. As long as ‘secrets of national importance’ were not disclosed, the scientists employed were given the right to publish their work and to attend the meetings ‘held by the Learned Societies’. Salaries were generous, particularly for the senior positions, and the Committee ‘expressed the feeling that nothing under £2,000 a year could be relied upon to induce a man of the first rank to accept the post of Director of Research at Porton’ – making it one of the most highly paid scientific jobs in the country. The Committee also concluded:

This was a crucial admission. No matter how loudly the British, or any other nation, renounced gas warfare in public, in secret they felt bound to give their scientists a free hand to go on devising the deadliest weapons they could, on the grounds that they had first to be invented, before counter-measures could be prepared.

Porton Down made use of this logic between 1919 and 1939 to carry out a mass of offensive research, developing gas grenades and hand contamination bombs; a toxic air smoke bomb charged with a new arsenic codenamed ‘DM’ was tested; anti-tank weapons were produced; and Porton developed an aircraft spray tank capable of dispersing mustard gas from a height of 15,000 feet. At the same time the weapons of the First World War – the Livens Projector, the mortar, the chemical shell and even the cylinder – were all modified and improved.

There was extensive human testing, often involving scores of men at a time. Some of the tests were so drastic, one wonders what could possibly have motivated men to go through with them. In 1922, for example, twenty ‘observers’ were placed in a gas chamber for ten minutes’ exposure (‘the limit of tolerability’) to the arsenic gas ‘DA’ and suffered

Mustard gas, ‘the King of Gases’, employed the most human volunteers. Just one experiment in 1924 involved forty men. In April 1928 large numbers of human observers were contaminated in five separate aerial spray tests. In the same year bricks were coated with mustard; after a fortnight men handled them and the vapour given off was found to be still powerful enough to cause burns ‘of a severe character’. In October 1929, ‘two subjects received copious applications of crude Mustard which practically covered the inner aspect of the forearm. After wiping the liquid mustard off roughly with a small tuft of grass the ointment (seven weeks old) was lightly rubbed with the fingers over the area…’¹⁶

This is merely a random selection of the sort of work which was done in Britain. Similar research was being carried out throughout the world. Italy established a Servizio Chemico Militaire in 1923 with an extensive proving ground in the north of the country. The main French chemical warfare installation was the Atelier de Pyrotechnie du Bouchet near Paris. The Japanese Navy began work on chemical weapons in 1923, and the Army followed suit in 1925. In Germany, despite the fact that Haber’s Kaiser Wilhelm Institute had been closed down in 1919, limited defensive work continued, later to form the basis of Germany’s offensive effort. And in 1924 the Military-Chemical Administration of the Red Army was established and Russian chemical troops were stationed at each provincial army headquarters.

Chemical weapons were not merely researched and developed – they were used. At the beginning of 1919 the British employed the ‘M’ device (which produced clouds of arsenic smoke) at Archangel when they intervened in the Russian Civil War, dropping the canisters from aeroplanes into the dense forests. The anti-Bolshevik White Army was equipped with British gas shells, and the Red Army are also alleged to have used chemicals.

Later in 1919, Foulkes was dispatched to India, and in August urged the War Office to use chemicals against the Afghans and rebellious tribesmen on the North-West Frontier: ‘Ignorance, lack of instruction and discipline and the absence of protection on the part of Afghans and tribesmen will undoubtedly enhance the casualty producing value of mustard gas in frontier fighting.’¹⁷ Many of the Cabinet were dubious, including the Secretary of State for India. Foulkes had little time for their scruples:

Foulkes had his way. Stocks of phosgene and mustard gas were sent out, while in the scorching heat of the Khyber Pass in midsummer, British troops trained in anti-gas suits. Large supplies of smoke shells were stored at Peshawar near the Afghan frontier for use in flushing-out rebellious tribesmen from their mountain hideouts. Major Salt, Chemical Adviser to the British Army in India, wrote that after ‘the usual talk about “clean hands” and “low-down tricks against the poor ignorant tribesman”… the Government have decided they will adopt a policy of using gas on the frontier.’¹⁹ The RAF is alleged to have used gas bombs against the Afghans. It would have made a murky chapter in Britain’s imperial history, and records were either not kept or were destroyed: there are today no operational accounts in the British archives.

Used against poorly-armed and trained insurgents, the imperial powers rapidly learnt that gas was a devastating weapon. Persistent agents like mustard could make favourite ambush positions untenable for weeks. Tear gas and smoke weapons, especially if used from the air, forced the enemy into the open where he could be more easily picked off. By 1925 the French and Spanish were employing poison gas in Morocco, and it had become clear that chemical warfare had found a new role, as a tool by which major powers could ‘police’ rebellious territories.

Yet despite its widespread development and use in the years following the First World War, gas warfare was still technically illegal. The Allied Powers described it as a ‘prohibited’ form of warfare at Versailles in 1919 and banned the importation and manufacture of poison gas in Germany for all time. Three years later, the Washington Treaty went even further: the ‘civilised Powers’ decreed that the banning of chemical warfare should ‘be universally accepted as part of international law binding alike to the conscience and practice of nations’.

Finally, in May 1925, under the auspices of the League of Nations, a conference on the international arms trade was convened in Geneva. Led by the United States, the delegates agreed to try and tackle the problem of poison gas, ‘with,’ as the Americans put it, ‘the hope of reducing the barbarity of modern warfare.’ After a month of wrangling in legal and military committees – during which the Polish delegation far-sightedly suggested that they also ban the use of germ weapons, then little more than a theory – the delegates came together on 17 June to sign what remained until 1997 the strongest legal constraint on chemical and biological warfare:

Thirty-eight powers signed the Geneva Protocol, among them the United States, the British Empire, France, Germany, Italy, Japan and Canada; the fledgling USSR did not attend.

‘The signing of the Geneva Protocol of 1925,’ as one expert has put it, ‘was the high-water mark of the hostility of public opinion towards chemical warfare.’²¹ Unfortunately, the anti-gas lobby had underestimated the strength of the interests ranged against them. Merely signing the Protocol was not enough to make it binding – individual governments had to ratify it. In many cases this meant a time lag of at least a year, and it was in this period that the supporters of chemical weapons struck back.

The United States Chemical Warfare Service launched a highly effective lobby. They enlisted the support of veterans’ associations and of the American Chemical Society (whose Executive declared that ‘the prohibition of chemical warfare meant the abandonment of humane methods for the old horrors of battle’). As has often happened since, the fight for chemical weapons was represented as a fight for general military preparedness. Senators joined the CWS campaign, among them the Chairman of the Committee on Military Affairs who opened his attack on ratification in the Senate debate with a reference to the 1922 Washington Treaty: ‘I think it is fair to say that in 1922 there was much of hysteria and much of misinformation concerning chemical warfare.’ Other Senators rose to speak approvingly of resolutions which they had received attacking the Geneva Protocol – from the Association of Military Surgeons, the American Legion, the Veterans of Foreign Wars of the United States, the Reserve Officers Association of the United States and the Military Order of the World War. Under such heavy fire, the State Department saw no alternative but to withdraw the Protocol, and reintroduce it at a more favourable moment. It was not to be until 1970, forty-five years after the Geneva conference, that the Protocol was again submitted to the Senate for ratification; it took another five years for this to be achieved.

Japan followed America’s example and refused to ratify (they finally did so in May 1970). In Europe, the various countries eyed one another cautiously. France ratified first, in 1926. Two years later, in 1928, Italy followed suit and a fortnight after her, the Soviet Union declared that she, too, considered herself bound by the Protocol. Only after Germany ratified in 1929 did Britain feel able to accept the Protocol: on 9 April 1930, five years after the Conference, Britain at last fell into line.

Many of the states which ratified the Protocol – including France, Great Britain and the USSR – did so only after adding two significant reservations: (i) that the agreement would not be considered binding unless the country they were fighting had also ratified the Protocol; (2) that if any other country attacked them using chemical or biological weapons, they reserved the right to reply in kind.

‘Justly condemned by the general opinion of the civilised world’ chemical weapons might be; abandoned they certainly were not. The Geneva Protocol was, effectively, a ban only on the first use of poison gas or germs. There was certainly no ban on researching and stockpiling chemical weapons. While the British Government stressed that Porton Down was only concerned with defensive work, full scale research into new weapons actually accelerated. A Brief History of the Chemical Defence Experimental Establishment Porton, the slim, forty-four page house history of Porton, is quite frank about the cynical way in which the public were deceived:

This ‘defensive’ work included ‘improvements to many First World War weapons, including gas shells, mortar bombs, the Livens Projector and toxic smoke generators’ and the development of ‘apparatus for mustard gas spray from aircraft, bombs of many types, airburst mustard gas shell, gas grenades and weapons for attacking tanks’. The various inventions were tested in north Wales, Scotland, and in installations scattered throughout the Empire, notably northern India, Australia and the Middle East.

The commitment by most of the world’s governments never to initiate the use of poison gas did not stop research: it simply made the whole subject that much more sensitive, and thus more secret. In 1928, the Germans began to collaborate with the Russians in a series of top secret tests called ‘Project Tomka’ at a site in the Soviet Union about twenty kilometres west of Volsk. For the next five years, around thirty German experts lived and worked alongside ‘a rather larger number of Soviet staff’, mainly engaged in testing mustard gas. The security measures surrounding Project Tomka ‘were such that any of its participants who spoke about it to outsiders risked capital punishment’.²²

In Japan, experimental production of mustard gas was begun in 1928 at the Tandanoumi Arsenal. Six years later the Japanese were manufacturing a ton of Lewisite a week; by 1937 output had risen to two tons per day. Extensive testing – including trials in tropical conditions on Formosa in 1930 – resulted in the development of a fearsome array of gas weapons: rockets able to deliver ten litres of agent up to two miles; devices for emitting a ‘gas fog’; flame throwers modified to hurl jets of hydrogen cyanide; mustard spray bombs which released streams of gas while gently floating to earth attached to parachutes; remotely-controlled contamination trailers capable of laying mustard in strips seven metres wide; and the ‘Masuka Dan’, a hand-carried anti-tank weapon loaded with a kilogram of hydrogen cyanide. Defensive preparations were equally thorough, and ran right down to masks for horses and camels (two feet long and eight inches in diameter) and masks, leggings and shoes for dogs.²³

The Japanese set about the study of chemical warfare with a dedication that at times bordered on fanaticism. The Army Chemical Warfare School was established in 1933 at Narashino, twenty-one miles east of Tokyo. It had a forty acre site and impressive facilities. The School Commandant, Major General Yamazaki, promised ‘just and severe punishment’ for those who failed to adhere to its code:

The students were all carefully selected officers. Most took an eleven month course. In twelve years the school turned out 3,350 chemical warfare experts.

There is now little doubt that from 1937 onwards the Japanese made extensive use of poison gas in their war against the Chinese. In October 1937 China made a formal protest to the League of Nations. In August 1938 they accused the Japanese of using mustard gas, and produced a variety of witnesses, including a British surgeon who had treated nineteen gas casualties wounded while fighting on the Yangtze Front. Chinese peasants are said to have been driven from caves and tunnels by gas and then massacred by waiting Japanese troops.

Like the British and French before them, the Japanese discovered that gas was a superb weapon when used against poorly trained and largely ignorant opponents. Operations in China became text book examples of the use of chemical weapons – so much so that the Japanese actually turned the accounts of their gas attacks into a series of pamphlets entitled Lessons From the China Incident, and distributed them among the students at the Narashino school. One Soviet authority estimated that a third of all Japanese munitions sent to China were chemical, and that ‘in several battles up to 10 per cent of the total losses suffered by the Chinese armies were due to chemical weapons’.²⁵

The Italians made use of chemicals in their invasion of Abyssinia in much the same way. In 1935 and 1936, 700 tons of gas were shipped out, most of it for use by the Italian air force. First came torpedo-shaped mustard bombs. Then, in early 1936, the Italians tried out the new technique of aerial spraying. In a speech to the League of Nations, Abyssinian Emperor Haile Selassie described how ‘groups of nine, fifteen and eighteen aircraft followed one another so that the liquid issuing from them formed a continuous fog… soldiers, women, children, cattle, rivers, lakes and pastures were drenched continually with this deadly rain.’²⁶ According to the British, the Italians were using 500 lb ‘spray type’ bombs filled with mustard gas. They functioned by means of a time fuse. When the bomb was ‘about 200 feet above the ground’ it burst open – ‘the liquid contents were scattered in the form of spray over a considerable area’.²⁷

Reports filtering out of Abyssinia gave some idea of the appalling suffering which mustard gas was capable of inflicting on defenceless natives. The liquid lingered on the ground and on foliage, contaminating not only troops but peasants passing through the bush. Walter Holmes of the London Times wrote of men ‘injured in the legs and lower parts of the body. In several cases, large areas of skin had been removed from the legs and thighs; some of these men had also suffered extremely painful burning of the genital organs.’ Italian planes, Holmes reported, flew low over the countryside spraying mustard in a ‘fine rain of corrosive liquid’. There was no protection and no escape, and large numbers of natives ‘received ghastly injuries to the head, face and upper parts of the body’.²⁸ Blinded victims could not make their way into the hills where the Red Cross had first aid posts; untreated skin wounds were infected with gangrene. Dr John Kelly, Head of the British Red Cross in Abyssinia treated 150 cases of ‘severe burns’ from mustard gas in three days at the end of February 1936: ‘many of the patients were women, children and infants’. In the course of two weeks in March he treated a further 200–300 victims, many too blind to make their way to his ambulance. ‘A large number of the burns treated were of a terrible nature.’²⁹ The reports of Holmes and Kelly – including photographs of the victims – joined the bulging file on Italian use of gas held by the League of Nations.

This was not war, but slaughter. Abyssinia was little more than a proving ground for the murderous modern gas weapons which had been developed (in Porton’s words) ‘under the rose’ of the Geneva Protocol since the end of the First World War. Just as the German bombing of Guernica a year later warned how the bomber could be used against civilians, so Abyssinia showed how effective gas warfare had become. Around 15,000 Abyssinian soldiers were killed or wounded by chemical weapons – almost a third of the total casualties for the entire war.

In the disintegrating peace of 1936, the Italian use of gas was described by the British Prime Minister, Stanley Baldwin, as a ‘peril to the world’ and he voiced the question which was now in the minds of most of the world’s governments: ‘If a great European nation, in spite of having given its signature to the Geneva Protocol against the use of such gases, employs them in Africa, what guarantee have we that they may not be used in Europe?’³⁰

The answer, obviously, was none. After Abyssinia British Intelligence was in no doubt about Italian intentions. ‘It may be concluded,’ wrote MI 3 in August 1936, ‘that in a future war she would employ the gas weapon unless special circumstances render such a course inadvisable.’³¹ Three months later, in November, the British Government announced that everyone in the United Kingdom was to be issued with a gas mask. In September 1938, at the time of the Munich Crisis, over thirty million were issued to the public. There were ‘cot respirators’ for babies, and specially designed ‘invalid hoods’ for the sick and elderly. Official Governments films warning of the dangers of gas were shown in cinemas, while signs in buses and on underground trains exhorted the population to carry their masks at all times. In homes throughout Europe the same scenes were repeated as families tried on gas masks. The French even developed protective measures for pigeons.

While their civilians trained in defence, the world’s major powers embarked upon large-scale chemical rearmament. In 1936 the French built a factory to produce phosgene at Clamency, at a cost of eighteen million francs.³² A year later, First World War mustard gas and phosgene plants at Edgewood Arsenal in the United States were put back into action. New factories were opened by the Soviet Union at Brandyuzhsky, Kuibyshev and Karaganda. The British – with the ‘whole-hearted co-operation’ of Imperial Chemical Industries (ICI) – began building a new mustard gas factory at Sutton Oak near St Helens in Lancashire in 1936; two more factories were planned. On 2 November 1938, the Cabinet ordered the creation of an industrial productive capacity of 300 tons of mustard gas per week and a reserve of 2,000 tons.

British Intelligence conjured up a frightening picture of a Europe swarming with scientists and chemists at work on war gases. German research on chemical warfare was said to have ‘been pursued unremittingly’ since the First World War. Laboratories were at work in Berlin and in the Ruhr, and three experimental centres were said to exist – one near Munster and two others at Wunsdorf and List. Six aircraft at a time, flying ‘simultaneously or in relays’ were believed to take part in low-altitude spray trials. Overall, capacity was estimated to be greater than that attained during 1918. The Italians were reported to be capable of producing twenty-five tons of mustard and five tons of Lewisite a day, as well as possessing an ‘unstated capacity for phosgene, chloropierin and DM’. In the USSR training of chemical troops was said to be pushed to ‘almost fanatical limits’: ‘Of all countries, Soviet Russia appears to devote the greatest effort to developing the chemical arm.’ (The Germans shared British misgivings, and estimated the number of Soviet scientists directly involved in chemical warfare at over 6,000.) The report concluded: ‘Massive bombardment may be anticipated with concentrations of all available supplementary chemical weapons and close co-operation of aircraft. In retiral, use will be made of large-scale contamination of areas by chemical lorries and low flying aircraft, together with heavy contamination by mines, etc, of bridges and traffic centres. Aerial attack with HE [high explosive] and incendiary bombs may be followed by gas.’³³

Faced with this alarming assessment, and with war only a few months away, in May 1939 the British and French began to collaborate on a joint chemical warfare policy. According to a ‘Most Secret’ report³⁴ by the head of the British delegation, the attitudes of the two governments were broadly similar. ‘The French think that the chemical industries in Germany and Italy are so highly developed that the use of gas by these countries may be regarded as certain. Their delegation had not considered the possibility that either Germany or Italy might refrain from using gas in the early stages to avoid retaliation in kind’.

Against this certainty, the French had ready a considerable arsenal, including four and a half million grenades oeuf – grenades resembling large eggs filled with mustard gas to be dropped in clutches of fifty at a time; they had no fuses, being designed simply to break on impact. The French were shown to have placed far greater reliance than the British on phosgene, using it as a filling ‘for projectors, for artillery shell and for large aircraft bombs’. One ingenious device was ‘a 200 kg bomb filled with phosgene. This contains a bursting charge designed to blow out any earth which may have fallen in behind the bomb after penetration.’³⁵

On their side, the British offered the French an unrivalled expertise in a method of chemical warfare which Porton had made its own: high altitude spraying of mustard gas. British bombers were now able to accurately release spray from a height of 15,000 feet, out of danger from anti-aircraft guns. With no warning, enemy troops could be drenched in a drizzle of mustard gas which the British calculated would contaminate ‘100 per cent of the personnel in the area affected who are not under cover’.³⁶ The secret was a variant of conventional mustard (HS): three times as powerful, it was code-named ‘HT’, and had a very low freezing point. The French were greatly excited by the discovery: it was regarded as of ‘the first importance’. The British gave the French one of their 250 lb spray tanks and a series of joint trials was arranged – first with a harmless substitute for mustard gas at Bourget in France, and then with the real thing at the vast French proving ground in the Sahara.

French scientists were invited to Porton, and their British counterparts permitted to visit France’s gas factories ‘to witness manufacture’. After a ‘complete and frank pooling of information’ the two sides parted on 12 May. A variety of sub-committees were established; offensive weapons were dealt with on Sub-Committee E. By the time its members met again in September, the war with Germany had already begun. Few doubted that general chemical warfare would take place and that – as a Secret Intelligence Summary put it – ‘if the Germans deem it expedient to introduce gas warfare it will be pursued with their characteristic vigour, ingenuity and ruthlessness’.³⁷

Even fewer are likely to have questioned another of the Summary’s conclusions: ‘it is not thought that any important new war gas has been discovered’. In fact, the Germans had secretly developed a new series of gases dozens of times more deadly than anything the Allies possessed. Had Hitler known of his enemies’ ignorance, the Second World War might well have taken a different course.