They're feeding the creature a compound of sulfur. Now, sulfur serves it as our vitamins do us.

6 seconds sound clip from the 20 Million Miles to Earth (1957) movie soundboard.

You can hear this line at 01:02:25.309 in the Blu-ray version of the movie.

Quote context

[...]

- We hope this electrodynamometer will enable us to complete our examination of aural passages.

- Could you give us any positive statement on your progress so far, doctor?

- So far, we have come to one conclusion. The creature's olfactory system is more highly developed than any known on this planet.

- You'll find Doctor Uhl on the platform. He's the man in charge.

- Sixty-seven CC's. Correct?

- Si, esattamente, sessanta sette.

- They're feeding the creature a compound of sulfur. Now, sulfur serves it as our vitamins do us.

- Grandpa, will you need me anymore?

- No, no. Grazie.

- You caught me unprepared.

- I've been cooking over a hot creature all day.

- You're getting lovelier every time I see you. Or is it the lights in this room?

[...]