By Dr. Emily Munro
We hardly speak of it anymore but in the 1980s, acid rain was a household discussion topic. Acid rain – caused mostly by emissions of sulphur dioxide from coal-fired power plants and factories – has now largely been controlled in Europe by transitioning away from coal. In the 1970s, 1980s and 1990s, however, it was blamed for acidifying lakes, stripping tress of their leaves and eating away at historic buildings and metals. It felt like a modern problem but 100 years earlier, acid rain had already been described by a Scottish chemist named Robert Angus Smith.
Smith was born in Pollokshaws and went to Glasgow High School. He studied Divinity at Glasgow University (at a very young age) for a short time but left before graduating. Smith eventually became a personal tutor. When the family he was working for left Scotland for Germany, he followed the opportunity and it was there he began studying chemistry under the guidance of Professor Justus von Liebig.
CHLOROFORM, FERTILIZERS AND THE ALKALI ACT
Liebig is known as an inventor of chloroform, the news of which travelled to Scotland via another of his Scottish students, Lyon Playfair (leading to the pioneering anaesthesia work of Dr James Simpson who treated Queen Victoria with chloroform when she birthed her son Leopold). But Liebig made another significant discovery that continues to shape our world and how we produce food. He found that plants take in nitrogen and carbon dioxide from the air, as well as minerals found in soil. This understanding led to the development of chemical nitrogen-based fertilizers. Liebig also understood that plants improved the air by producing oxygen.
When Smith returned to Britain it was to assist Playfair, now Honorary Professor at the chemical laboratory at the Royal Manchester Institution. Manchester was one of the most highly industrialised parts of England and heavily polluted. Playfair served on the Health of Towns Commission and brought Smith along with him. As they gathered evidence for their report on public health, they witnessed scenes of abysmal poverty and squalor. At the time, fears of cholera epidemics abounded and there was an urgency to understand the causes of disease and educate the public on these. For several decades there had been concern over the gasses emitted by chemical manufacturing plants and finally in 1863 (perhaps mainly thanks to landowners whose woodlands were being damaged) the Alkali Act was created to combat, initially, hydrogen chloride pollution from Leblanc alkali works. To do this, an inspectorate was formed with Smith at the helm. He had a small team to monitor the country which meant that many operators could slip through the net. To counteract this, Albert Fletcher (one of Smith’s inspectors), developed an aspirator that could take air samples from chimney flues. It was sealed against tampering.
THE BRIGGAIT AND BOAR’S HEAD CLOSE
The work can’t have been easy. Manufacturers were unhappy about interference in their operations and relations with the Inspectorate inevitably strained. Smith reported to parliament annually and managed to win over industry by explaining that complying with the law was better than facing a legal challenge. Self-regulation therefore become built into pollution controls and remains crucial today.
Smith became fascinated with the composition of chemicals in the air. He undertook some short-lived experiments on carbon dioxide concentrations, shutting volunteers in a lead chamber with burning candles and measuring their breathing rate and pulse (these went up the higher the concentrations of CO2) (see Gibson & Farrar). His book Air and Rain: the beginnings of chemical climatology (1872) attempts to draw some conclusions about impurities in the air using the measurements gathered by the Alkali Inspectorate. In it he describes how he discovered sulphuric acid in rain (in 1852) as he was unable to measure the air itself. He advises “rainwater in town districts… is not a pure water for drinking” (p227) and over time will lead to the deterioration of mortar (p444).
One of the most polluted locations Smith collected data from was the Briggait: “one of the worst is from a height of 82 feet, being collected on a church-tower in Bridgegate. This does not point to any small local accumulation of mere dust, but a complete filling of the atmosphere. The place was above all the houses around”(p262). The Glasgow locations Smith monitored included Western, Gorbals and Calton Police Stations, New City Road and St Rollux. Only one place was more polluted by acids than the church steeple at Bridgegate, a place called Boar’s Head Close not far from where the Glasgow City Heritage Trust offices are based today. Both it and the Briggait were surrounded by cotton factories, dyeworks, tanneries but also public houses, churches, schools – places where many people lived and worked, in tight proximity to one another.
It was reported that Smith felt Glasgow industry was acting too slowly to combat noxious fumes: “if they have avoided law they certainly have not avoided deserving blame,” he said (The Herald July 17, 1872). The same newspaper noted that Glasgow’s high death rate had attracted speculation over the role of manufacturer’s vapours in contributing to mortality. The journalist reporting ventured: ‘When the causes of pollution either of the earth or the air are clearly and distinctly known, we are half way to a cure of the evil.” And yet, at the time, coal was not a focus of enquiries.
AIR AND RAIN
Air and Rain is hard to draw conclusions from but Smith does make an appeal at the end to reduce overcrowding. Glasgow, he says, has ‘inferior air’: “Let those courts, alleys, and streets which show the greatest mortality and the worst air be destroyed or improved without foolish mercy” (p548).
Smith has been described as “a half-trained amateur” (Gibson & Farrar), not a great scientist whose work should be cited far least admired. This seems a little unfair. If nothing else, the man who is known for the term ‘acid rain’ was a principled, socially-minded person who wanted to hold polluters to account. Today he can be remembered as such.
Smith, Robert Angus 1872 Air and Rain: the beginnings of chemical climatology
Gibson, A. & Farrar, W.V. 1974 ‘Robert Angus Smith, F.R.S, and “Sanitary Science,”’ in Notes and Records of the Royal Society of London, 28 (1974), 241–262
The Glasgow Herald, Wednesday 17 July 1872 p4
Dr. Emily Munro is a writer and curator of moving image at the National Library of Scotland. Emily’s feature-length documentary ‘Living Proof – A Climate Story’ explores Scotland’s relationship to the climate crisis and the environment using archive footage.