§ Of Túrin Turambar The Silmarillion

Then he wrenched out the sword, but a spout of black blood followed it, and fell on his hand, and the venom burned it. And thereupon Glaurung opened his eyes and looked upon Turambar with such malice that it smote him as a blow; and by that stroke and the anguish of the venom he fell into a dark swoon, and lay as one dead, and his sword was beneath him.