This was a short story from the early 70s where hippies create a better world by putting cannabinoid oil into postage stamp glue. Very short and funny. Asimov perhaps?
I did a quick Google search for "cannabis in stamp glue short story -canada" (Canada's recent legalization of marijuana would dominate search results without the subtraction) led me to the short story "How Henry J. Littlefinger Licked the Hippies' Scheme to Take Over the Country by Tossing Pot in Postage Stamp Glue" by John Keefauver, which can be found in the 1975 anthology Alfred Hitchcock Presents: Stories to Be Read with the Door Locked.
I was unable to find a synopsis, though I assume the title is fairly self-explanatory. The anthology itself is available to borrow at the Internet Archive.
The story is about a young man who was a hippie but never smoked weed. The hippies, led by a big man, instruct Henry to get a job at the factory where they add the glue to the stamps, tossing pot brownies into the glue pot. The big man wanted to take over the country by getting everyone high, because as everyone knows, smoking weed makes you into a hippie, all except Henry for some reason. Also Henry is a severe diabetic and couldn’t eat the brownies, making him a perfect candidate for the job, as we all know, hippies are super unreliable around pot brownies and in general, Henry didn’t smoke and couldn’t eat, perfect man for the job right?
So Henry gets the job and begins tossing brownies in the glue and sure enough the country is getting high and becoming more hippieish by the day! The plan is working except Henry is getting bored just throwing them in and starts thinking of more interesting ways of getting them into the glue, and that’s where the trouble starts. He bounces them off an elbow, off his head, hook shot into the glue, off his knee, off his boot, and then one day he gets the idea to spit one into the glue.
So he does it, and for the first time in Henry J. Littlefinger's life he tastes sugar, and he kinda likes it. He kinda likes it a lot and spitting them in becomes his new favorite way to get them into the pot because every time he gets a little sweet taste until one day his spit doesn’t spit out and he swallows a brownie. And just as we all know that getting high makes you a hippie, for Henry it was different because he was a hippie without it, so naturally getting high turned Henry into a square.
I won’t tell you what happens next you gotta read the book.