Less than a tablespoon of liquid Nicotine can kill an adult.  Nicotine is a powerful stimulant and it need not be consumed--it just needs to come into contact with your skin.  In a case out of Kentucky, a woman was rushed to the hospital with heart failure when her e-cigarrete broke in her bed and she absorbed the concentrate by contact.  But adult incidents are far less common than children.  60% of these cases involve very small childrent lured by the bright colors and interesting fruity flavors now popular for Nicotine.  When use by a child-vomiting is immediate but death can follow quickly.   Liquid nicotine is now offered on the internet by the barrel, at $195/gallon for 10% Nicotine solution.  

For the full story by Matt Richtel:   Matt's NY Times Story