It found its way into western medicine by way of Dr. Richard Mead in 1745. He suggested that drowning victims could be resuscitated by giving them a tobacco enema, or in medical terms a glyster. Where did he get the idea? Maybe from Native Americans who used smoking tobacco and tobacco enemas to treat a variety of ailments in humans and animals.
The nicotine was thought to encourage the heart to beat quicker, which would invigorate the respiratory system. It was also thought to warm the person up and dry out any excess moisture. Warming and stimulation were considered the appropriate treatment for apparent death back in those days. Tobacco smoke was a Win-Win! Sometimes they would blow the smoke into the victim’s mouth or nose, but many doctors preferred the enema method - you know how doctors are.
In 1774 two doctors – Hawes and Cogan – started a group called The Institution for Affording Immediate Relief to Persons Apparently Dead From Drowning, which - thankfully - later changed its name to the Royal Humane Society. The old one sounded like it was named by Derek Zoolander.
Anyways, this group placed these tobacco enema kits (with tubes and bellows) up and down the river Thames in London like 18th century defibrillators. Good thing too, because before that people would just use whatever was on hand, usually their regular pipe that they would stick the mouthpiece in the rectum and blow down on the bowl end. The society would even pay four guineas to anyone who revived a drowned victim, which is just shy of one troy ounce of pure gold.
Another doctor in 1774 came up with a catchy little rhyme to help spread the word.
Tobacco glyster, breathe and bleed.
Keep warm and rub till you succeed.
And spare no pains for what you do;
May one day be repaid to you.
This practice became hugely popular not only for drowning but for treating everything from headaches to diseases like typhoid and cancer - because why not. It reached its peak in 1811 when a scientist discovered that nicotine was actually toxic to the cardiac system and slowly fell out of use as word spread.
So for about 60 years someone would literally blow smoke up your arse, and thought they were helping you out!
Nobody knows the true origin of the saying. It could have come to be used because the process of blowing smoke up someone's arse did not resuscitate people, it was a lie. So if you are blowing smoke up someone's arse you are appearing to do something to help them, but actually aren't.