משנה אויף ישעיהו 22:5

What is ‘mixed blood? The blood of a corpse of which an eighth [of a log] came out during his lifetime and an eighth after death, the words of Rabbi Akiva. Rabbi Ishmael says: a quarter [of a log] during his lifetime and a quarter after death. [If] a quarter [of a log] is taken from both of these: Rabbi Elazar bar Judah says: both of these are as water. What then is ‘mixed blood’? It is that of a crucified person whose blood is streaming forth and under whom is found a quarter [of a log] of blood it is unclean. However a corpse whose blood drips forth and under whom is found a quarter [of a log] of blood, [the blood] is clean. Rabbi Judah says: not so, but that which streams forth is clean and that which drips forth is unclean.