There is some ambiguity as to whether guillotine is actually completely instant or painless: http://www.straightdope.com/columns/read/1172/does-the-head-remain-

There is some ambiguity as to whether guillotine is actually completely instant or painless: http://www.straightdope.com/columns/read/1172/does-the-head-remain-briefly-conscious-after-decapitation http://www.straightdope.com/columns/read/1172/does-the-head-...