Dostoyevsky's The Idiot, regarding the guillotine

"At last he began to mount the steps; his legs were tied, so that he had to take very small steps. The priest, who seemed to be a wise man, had stopped talking now, and only held the cross for the wretched fellow to kiss. At the foot of the ladder he had been pale enough; but when he set foot on the scaffold at the top, his face suddenly became the colour of paper, positively like white notepaper. His legs must have become suddenly feeble and helpless, and he felt a choking in his throat--you know the sudden feeling one has in moments of terrible fear, when one does not lose one's wits, but is absolutely powerless to move? If some dreadful thing were suddenly to happen; if a house were just about to fall on one;--don't you know how one would long to sit down and shut one's eyes and wait, and wait? Well, when this terrible feeling came over him, the priest quickly pressed the cross to his lips, without a word--a little silver cross it was- and he kept on pressing it to the man's lips every second. And whenever the cross touched his lips, the eyes would open for a moment, and the legs moved once, and he kissed the cross greedily, hurriedly--just as though he were anxious to catch hold of something in case of its being useful to him afterwards, though he could hardly have had any connected religious thoughts at the time. And so up to the very block.

"How strange that criminals seldom swoon at such a moment! On the contrary, the brain is especially active, and works incessantly-- probably hard, hard, hard--like an engine at full pressure. I imagine that various thoughts must beat loud and fast through his head--all unfinished ones, and strange, funny thoughts, very likely!--like this, for instance: 'That man is looking at me, and he has a wart on his forehead! and the executioner has burst one of his buttons, and the lowest one is all rusty!' And meanwhile he notices and remembers everything. There is one point that cannot be forgotten, round which everything else dances and turns about; and because of this point he cannot faint, and this lasts until the very final quarter of a second, when the wretched neck is on the block and the victim listens and waits and KNOWS-- that's the point, he KNOWS that he is just NOW about to die, and listens for the rasp of the iron over his head. If I lay there, I should certainly listen for that grating sound, and hear it, too! There would probably be but the tenth part of an instant left to hear it in, but one would certainly hear it. And imagine, some people declare that when the head flies off it is CONSCIOUS of having flown off! Just imagine what a thing to realize! Fancy if consciousness were to last for even five seconds!"

LINK to Fyodor Dostoyevsky The Idiot Part I: Chapter V