On when to spit, and when to swallow

The country boy had done good, and had moved up to the thriving metropolis. It was the mid 60s, and as a young man in a fairly high profile job within one of the country's national banks, he worked hard and played hard. One evening he found himself in much imbibement of the foamy brown liquid better known as "beer" and was making new friends in the local pub with his tales of his youth in a small city in the wilds of Wales. Such tales involving many dates and his moggy 1000. As the "beer" took control of his faculties, he bragged more and more about things he could and couldn't do. This was, by enlarge, fun and no one took him seriously. Except for the man who'd been sat listening to this young whipper snapper and his tales of mirth, who wasn't the centre of attention and felt the green eyed monster appearing from inside. Suddenly he stood up.
"Y-y-y-you're so g-g-g-great, with y-y-y-your boasting. I b-b-b-bet you can't d-d-d-drink what I g-g-g-give you," he stammered.
"How much?" the 'whipper snapper' asked. "How much do you bet?"
"Wha? Oh, OOooh, h-h-h-how about £100?" he offered.
Not an inconsiderable amount in the 1960s, actually equalling about £1,500 in today's money.
"You're on," he said, expecting some kind of lethal cocktail from the bar.
"That," said the challenger, pointing across the bar.
Everyone, following the line of his finger, set eyes upon something you no longer find in pubs. There, at the end of the bar in the corner was the spittoon.
"But tha's not fair! I was expecting a bad pint or something."
"£100, and if you don't do it, you owe me."
The spittoon, frothing and bubbling with all kinds of unpleasant things, including chewing tobacco and the by-product of a man with a cold, was poured into a pint pot.
Slowly, nervously, he took the unsavoury mixture to his lips, and gulped. At which point it all seemed to gel together, and all slid down in one go. In his words, "once you started, it was difficult to stop."
"*boilk*" he said, and was seen leaving at a rate of knots for the gents, where presumably he passed a new record for heaving consecutively.
He cleaned himself up, and returned to the bar, now rather more sober than when he'd left and his fresh pint. Oh, and his winnings.

Today, he's 66. Penblwydd hapus Dad. I'll leave a drink at the bar...