Ahhh, beautiful! Wait, what? *cough cough* Somebody invent gas-masks fast...
What became known as the Laki Haze in northern Europe was actually a combination of hydrofluoric acid & sulfur-dioxide that moved eerily through the streets of the highly religious parts of England and France, turning day into a perpetual reddish twilight, killing people and generally made life miserable for the hard working English, and wine drinking French. Remember that his was before industrial robots and tractors so there was a lot of hard manual labour, usually an exercise where you appreciate the fresh Enlightenment air.
Not invented, thankfully not industries either
The reason for this excitement was that rising magma collided with groundwater, creating phreatomagmatic explosions and simultaneously opened 130 craters that spent the next 8 months spreading death and terror over the neighbourhood. That sort of thing was frowned upon even back then, fortunately nobody had invented satellites either so they had no idea death came from Iceland, most people probably didn't know that there was an Iceland at all.
Not invented. Which was bad because no GPS:es meant people got lost all the time. But good because nobody had to spend a Saturday watching reruns of The Hills with their girlfriend.
In the beginning the Icelanders stood in awe watching 1400m high lava fountains, while the Brits brushed ash of their Frocks. Then started The Mist Hardships where 25% of the Icelandish population died in the famine that followed after their animals began dying of dental and skeletal fluorosis (tell your dentist that next time he tries to force fluorine-tables down your throat). Things got so bad they where forced to invent new dishes, like the scrumptious Book-soup where they actually boiled the pages that was made of animal skins. It's strangely absent from modern cooking books. Nigella, I have a top tip! Gimme a call.
A freakishly hot summer combined with a high pressure zone over Iceland meant that the poisonous, sulphuric air moved like a freight-train down over Norway, Czechoslovakia, Germany, France and ending up in Great Britain in only 6 days (which is much faster than a train actually, all trains being delayed by insurmountable obstacles like leaves and a small breeze).
And while English captains stood on shore cursing at the blood red sun, unable to take to the sea due to the thick mist, some 23 000 Brits died around them. That's around 100.000 in todays currency.
Besides being unhealthy to breathe the haze also caused weather worthy of a Roland Emmerich film.
Epic thunderstorms with lightnings that killed horses and men, hails that killed livestock and torrential rains.
What followed was a bitterly cold and cruel winter killing at least 8000 more than usual winters.
Not invented, which meant that the Greeks had to pay their own bills.
The British had excellent records over their dead which makes it quite easy to calculate how many more died during these months than normally. The French (being very French) didn't bother writing down such information though, they kept busy shouting at the haze, getting priest to exorcise it and probably tried to get it into a guillotine (killing things in guillotines being their national sport at the day)
Invented, which made some people shorter, and a lot of crazy French revolutionaries ecstatic
The extreme weather actually screwed up the French crops so much that the ensuing famine and poverty (as this was before the EU was invented the Germans wouldn't bail out the frogs) may have kick-started the French Revolution. Although, knowing the French, it would probably have happened anyway sooner or later.