Wendy Simms: What do you think turned it green?
Hodges: It might be sulfur.
Wendy Simms: Sulfur is a naturally occurring component of blood.
Hodges: But in massive doses, it tends to turn blood a blackish, avocado green. When the sulfur atom attaches to the hemoglobin molecule, it turns green. Which is why First Officer Spock's blood is green in Star Trek.
Wendy Simms: No, it's not.
Hodges: Yes, it is. Trust me, I'm an expert.
Wendy Simms: Well, apparently not, because otherwise you would surely know that the oxidizing agent in Vulcan blood is copper and that is why his blood is green. I mean that and the fact that he had a Vulcan father since his mother was actually human. And furthermore, he was promoted to Captain just prior to Star Trek II and then he retired as a civilian ambassador.
Hodges: You're like a geeky, nerdy guy trapped in a woman's body.
Wendy Simms: So are you.
Hodges: Anytime you need a sniffer to detect it, my nose has the cyanide gene.
Gil Grissom: What gene turned your nose brown?
Catherine Willows: [Referring to a burned spot on the floor] Now, get down and sniff the rug.
Hodges: That's all they ever want.