Right, Grain alcohol is just that; derived from grain and the "cane" is made from sugar, basically as pure as you can get outside a lab. To give you a reference, on quart dammed near knocked out myself and four other adult men.
While in college, I worked as a TA in an embryology lab. I often wondered why the 100% pint bottles of alcohol had a tax stamp on it like a liquor bottle, a few friends and I found out why! Wow!. Once you open the bottle of 100%/200 proof, it immediately becomes lesser percentage as alcohol has an affinity for attracting moisture from the air making it "weaker" at 195 proof
Tom