that's the first month that pot was legal to sell for nonmedicinal purposes in that state. 2 million! tax revenue. the new legalized marijuana industry is a big business. cnn's ground breaking reporting on weed continues tonight at 10:00, eastern time. that's when dr. sanjay gupta's special, which is "weed 2: cannabis madness" gets under way. we have a preview of dr. gupta's latest marijuana documentary. have a look. >> let's talk about marijuana and your brain. it's a rather complicated process, so let's start off with what's familiar to you. thc. thc is the chemical in weed that gets you high. you feel light-headed, feel giddy. sometimes relaxed. marijuana you can smoke it, you can eat it and and inhail it with a vapor pen or consume in an oil form. it's especially good for little kids, taking as a medicine. no matter the method, thc goes through your bloodstream and into your brain. and there the thc will latch on