I stupidly drank some. It was 'only a mouthful' (as I possibly had to explain later), but the effect was more or less like amyl nitrate (as I realised years later) the main chemical in popular club drug poppers. I went into an instant spasm, my brain fogged, my eyes were apparently a bright bloodshot red, my nose streaming, and I couldn’t talk. I remember the other kids backing away from me, their faces either amused or horrified. Think about moments in films when say the Phantom of the Opera reveals his scarred face, or the creature busts out of Kane's chest in Alien. I was given that sort of room.
When Mr Bulos, our Egyptian biology teacher, came back in, he saw at once what had happened, led me to the sink and pressed on my tongue with something and tickled my throat to make me vomit. He very kindly took me to the school nurse, and I can't really remember what happened next. As Mr Bulos was mostly NOT particularly kindly in general, I got in a lot of shit about it.
Mr Bulos was five feet nothing, and always wore a white coat over his tweedy suit. He was the first person I ever noticed wearing orange shoes - well, that highly polished bright brown that just looks old-school weird. He kept his own grumpy counsel, and was rarely friendly, but always fair, and a great teacher. Biology was the only branch of science from which I came away with a little understanding (perhaps aided in part by my formaldehyde adventure). He had been at school with Omar Sharif. I wondered later whether it pissed him off that Omar Sharif was mega and he was stuck teaching boys who, among their other drawbacks, were stupid enough to drink formaldehyde.