The ploughman and the volcano

It would come as a surprise if something truly big, important or defining had been omitted from the Robert Burns story. And yet …

Whitsunday in Kirkjubæjarklaustur: June 8, 1783. Over breakfast, Pastor Jón Steingrímsson went through his Sunday sermon, making corrections, adding relevant quotations. At 9am, the morning quiet was shattered by a series of ear-splitting, gut-wrenching, thunderous booms. One of the largest volcanic eruptions in modern history had begun.

In Iceland, Steingrímsson is a folk hero, whose courage and calm in the face of disaster is the stuff of legend. He kept a remarkable journal, penned with a scientist's eye for detail, which is the most important eyewitness account of what has been called the Great Laki Eruption of 1783. "It began with the Earth heaving upwards, with a great screaming of noise and winds from its depths, then splitting asunder, ripping and tearing as if a crazed animal were tearing something apart."

Spectacular as they were, the lava fountains - jetting up to 4,500 feet in the air - soon died down. Laki was essentially a fissure eruption, opening like a zip in the Earth's crust. When the magma, ash and gases were exhausted, the fissure closed - then a second one zipped open. Then another. For eight months Laki belched its poisons into the Icelandic air, gouging a 17-mile long scar, now known as the Lakigígar, a series of 10 parallel fissures, each up to 5km wide.

Laki spewed up 15 cubic kilometres of lava in total, the third biggest lava eruption since the end of the last Ice Age. It covered about 600 square miles of land, engulfing 20 farms, killing 215 people and releasing eight million tonnes of toxic fluorine gas, which combined with falling ash then worked its way into the food chain. Sheep, cattle and horses perished; crops were buried in ash and a starving population boiled pages of books to try to extract nutrition. Almost 10,000 Icelanders died as a consequence of Laki; a quarter of the country's population. By the beginning of July 1783, the whole of Europe and even Russia, China, North Africa and North America had been affected.

Laki released a colossal 120 million tonnes of sulphur dioxide, which reacted with atmospheric water to form a continental-sized sulphuric acid cloud. At its peak, the haze covered a quarter of the planet's surface.

Benjamin Franklin, the US ambassador in Paris, wrote of "a constant fog" over Europe and much of North America; the English naturalist, Gilbert White, described "alarming meteors", "tremendous thunderstorms", a lingering, smoky fog and heat "so intense that butchers' meat could hardly be eaten on the day after it was killed; and the flies swarmed so in the lanes and hedges that they rendered the horses half frantic". Fierce electrical storms swept Europe, unleashing lightning bolts that killed horses, and dumping hailstones big enough to destroy livestock.

Throughout July and August, the sulphurous cloud lay over Europe like a suffocating quilt. The poet William Cowper noted in his diary: "Such multitudes are indisposed by fevers in this country that farms have difficulties gathering their harvest. The labourers having been almost every day carried out of the field incapable of work and many die." Mortality rates spiked across Europe: in Britain alone, an estimated 23,000 people were killed by the Laki fog. It was the worst natural disaster in the country's history, and its devastating impact was wide-ranging.

All over the northern hemisphere, crops were ruined and harvests failed. Japan's rice crop was wiped out, resulting in the worst famine in the country's recorded history. Some environmental historians have speculated that food poverty linked to the Laki volcano may have contributed to the build-up to the French revolution of 1789.

Here in Scotland during the summer of 1783, newspapers recorded violent storms and hurricanes. On July 15, the Edinburgh Advertiser reported two fatalities, describing - in graphic detail - the victims' bleeding wounds and blackened bodies. For the country's farmers, it was a desperate time. Robert Burns, then 24, was working on his father's farm at Lochlie in the parish of Tarbolton, South Ayrshire. Cold winters and a terrible harvest the year before had impoverished many local farmers and even threatened famine. On June 21, the day before the poisonous cloud reached Britain, Burns penned a letter to a relative, reflecting gloomily about the precarious state of the local economy. "Farming is at a very low ebb with us," he wrote. "Our Landholders … stretch us much beyond what, in any event, we will be able to pay." To make matters worse, Burns's father, William Burnes, was not only seriously ill - "in a dying condition" - but also involved in a bitter legal dispute with their landlord over disputed rents for the Lochlie farm. He faced ruin or even jail.

Robert Burns wasn't in great fettle either. The year before, he had had a mental breakdown in Irvine, and had moved back in with his parents, three brothers and three sisters. His writing at this time was mostly imitative and self-conscious; he had produced little of note bar some gloomy melancholic verse. And his energies were becoming increasingly distracted by a group of local girls known as the Mauchline Belles.

With their father ill, and Burns's time increasingly consumed by litigation, the family laboured all summer in the Lochlie fields, unaware of the poisonous nature of the fog they were breathing into their lungs. Burns wrote few letters during the Laki eruption period and we have no account of how he felt, nor if any of the family fell ill. But the strange weather patterns were almost certainly having an impact. Burns's sister Isabella - who would have turned 12 around the time when the volcanic storms were raging - would later tell an interviewer about her childhood terror of thunder, mentioning that during one storm when she was 11 or 12, her father had to come out to the fields to take her home.

It also seems possible that the volcano's impact on the climate profoundly influenced Burns's attempts to make a success of agriculture. After William Burnes died, on February 13, 1784, the two oldest sons, Robert and Gilbert, abandoned Lochlie and took the lease to nearby Mossgiel farm. A few weeks later, Burns began his first venture as an independent tenant farmer. Initially, he was full of optimism and put his shoulder to the wheel: "I entered on this farm with a full resolution … I read farming books, I calculated crops; I attended markets."

His optimism proved ill-founded. "The first year from unfortunately buying in bad seed, the second from a late harvest, we lost half of both our crops; this overset all my wisdom, and I returned 'Like the dog to his vomit, and the sow that was washed to her wallowing in the mire'."

According to biographer James Mackay, Burns's candid admission that he'd bought bad seed led to the "the scorn of previous biographers, the consensus of whose opinion was that Burns was an indifferent farmer".

However, Burns needn't have been so hard on himself. The summer of 1783 was brutal. All over the country, barley and oats turned yellow and withered. The harvest came late and was of poor quality. A prolonged Arctic winter followed, with months of heavy snow, blizzards and icy frosts. Spring brought meltwater floods which left Mossgiel's badly irrigated fields waterlogged.

"As a result," commented Mackay, "almost all of the seed available for the 1784 sowing would have been of a very poor quality, giving yields in a ratio of four to one or even lower." The summer of 1784 was again exceptionally cold and harvests poor. The next winter was just as cold, with little respite the following spring. Another bad harvest followed. Burns had chosen the worst possible two years to begin life as an independent farmer. On November 1, 1785, as the reality of consecutive failed harvests kicked in, and on the day his younger brother John died, aged 16, he penned one of his most famous verses:

But Mousie, thou art no thy-lane

In proving foresight may be vain:

The best laid schemes o' Mice an' Men

Gang aft agley.

An' lea'e us nought but grief an' pain

For promis'd joy!

In 1786, with his personal life also in turmoil, Burns turned his share of the Mossgiel farm over to Gilbert and considered emigrating to Jamaica to work on a slave plantation. His death 10 years later is generally assumed to have resulted from rheumatic heart disease, possibly triggered by an episode of rheumatic fever some years earlier. Some biographers claim this illness can be traced back to an episode in 1781. Burns biographer Robert Crawford, however, suggests that his 1781 ailments may have been psychological rather than physical. Crawford makes a compelling case that Burns suffered from depression from an early age.

Unfortunately, Burns left us no letters from the Laki summer and commented on neither the dark sulphurous haze nor his own health during this period. However, a year later, an entry in the poet's Common Place Book, dated August 1784, suggests something wasn't right: "AUG - A prayer, when fainting fits, and other alarming symptoms of a pleurisy or some other dangerous disorder, which indeed still threaten me, first put nature on the alarm." This is followed by a gloomy poem: Misgivings In The Hour Of Despondency And Prospect Of Death.

In a letter to John Tennant on September 13, 1784, Burns elaborates: "I got so much better on Saturday as to be able to ride home, but I am still in a kind of slow fever."

James Mackay commented: "Contemporary eyewitness accounts quoted by Chalmers state that Robert's health gave way 'to a somewhat serious extent' that summer, implying that the bout in early September was a recurrence of the same problem. 'The movements of his heart were affected, and he became liable to fainting fits, particularly in the night-time.'"

Gilbert Burns described his brother at this time suffering from "a palpitation of the heart, and a threatening of fainting and suffocation in his bed, in the night time".

These are the earliest, most convincing evidence of Burns having a debilitating physical ailment. The medical effects of prolonged inhalation of sulphuric acid vapours are well documented; depending on how much is inhaled, serious lung and pulmonary conditions can arise. Heart disease, which can leave the body prone to fatal bacterial infections in later life, can also be triggered or exacerbated.

What is significant is that these feverish bouts occurred less than a year after the Laki haze. Was this the origin of the heart disease that would eventually kill Robert Burns? The evidence is far from conclusive, but the possibility exists.

His brother John had died on November 1, 1785, two years after the volcanic haze, aged just 16. There is no information on what killed him. His youngest brother, William, died five years later, aged 23, in a "putrid fever". Like Burns, the two brothers had been exposed to the toxic cloud for prolonged periods. Their father, too, had been finished off during the first volcanic winter. Even taking into account the proliferation of potentially fatal illnesses in the late 18th century, the question is raised as to whether Laki contributed to their premature deaths.

Aside from the possible impact on the family's health, what is remarkable about the aftermath of Laki was the revolution in Robert Burns's creative output. Perhaps it was a combination of extremes, living life in a heightened state of intensity, enhanced radicalisation through hardship and poverty, but through this time of turmoil and tragedy Robert Burns emerged as Scotland's most vital and important poet. During the pivotal years of 1784-1786 he wrote the verse that would make him Scotland's celebrated poet.

When The Kilmarnock Edition was published in the summer of 1786, the Bard had arrived. A close reading reveals several references to extraordinary natural phenomena such as blizzards, wasting winds, hoary frosts, floods, fierce electrical storms, despair, and, of course, skulking in the shadows, death. How much of this is the legacy of Laki can only be guessed at.

Given the intense scrutiny to which his life has been subjected, it is strange that no biography of Robert Burns to date has explored this episode. Then again, for some inexplicable reason, the Laki eruption seems to have been wiped from Britain's collective consciousness.