A pint of pure LSD (which would be crystals) would be 500 grams, or about a million hits (literally) I'm pretty sure that would kill you. LD-50's really only tell you two things. #1- toxcitity of one drug compared to another, and #2- mice are some tough motherfuckers! That said, nothing that would fit on a blotter could hurt you. OK, that's not exactly true, but unless your dealer is Bin Laden I wouldn't worry to much about nerve agent or ricin on your blotter. Kinda hard to recommend a dose on a drug I've never tried. The stuff you have, I mean, I've tripped plenty of times. 1-2 hits, for a first time, but don't worry that it will physically hurt you, at any sane dosage.