How were stethoscopes helpful in confirming death years ago?

I love what Dr. Edgar Berman wrote about doctors and stethoscopes in "The Solid Gold Stethoscope":

"His most important scientific instruments were the stethoscope and the thermometer. As to the stethoscope, which more or less identified the doctor as a doctor, it was mostly for effect. Not five doctors in a hundred could pick up the sounds of pneumonia or rheumatic fever, unless it was so far gone the death rattle drowned them out. But patients were duly impressed -- and believed in those two pieces of rubber tubing stuck in the ears as much as today鈥檚 patients believe in the electrocardiogram. The present generation of doctors brought up on the din of the Stones, tone-deaf from electric guitar trauma, might as well put those earpieces in their nostrils for all they hear." Dr. Edgar Berman, "The Solid Gold Stethoscope" p. 32

I suppose they were used to determine whether the heart had stopped beating. No heartbeat = dead. (unfortunate for those who had a very faint heartbeat that couldn't be detected)

Well, considering that doctors today use them to check your heart beat, I'm gonna guess, and this is just a guess, they used it to see if your heart was beating. I could be wrong.

You can also listen for breathing with a stethoscope.

Stethos are still helpful in confirming health. One confirms death by the following:

1. the eyes become luster less
2. there are no breathing movement of chest
3. if one keeps a mirror in front of nostrils it won't fog if person is dead.
4. pulse or heart sounds heard by stetho.