Sedative is to anesthesiologist as capital is to a "D.corporation". This is primarily because sedatives are used by the former to achieve their goals and capital is used by the latter.
When you use imagery in poetry it helps you to visualize it more or better.
Visual effect of poetry.
I would say this is an example of alliteration.
In The Red Badge of Courage, when Henry wakes up in camp the day after fighting, he first think he is in a Charnel place because the sleeping men around him look dead.
its c, someone reported my answer and it got taken down last time