What does " to kill at forty rods" mean?
It's about cheap & strong whiskey that is called forty-rod in some dialects.
It is so called from its alleged ability to kill at forty rods

What does "at forty rods" mean?

Thanks in advance!

Question

What does " to kill at forty rods" mean?
It's about cheap & strong whiskey that is called forty-rod in some dialects.
It is so called from its alleged ability to kill at forty rods

What does "at forty rods" mean?

Thanks in advance!

Answer

A rod is a unit of measurement.  It's about 5 meters.
So 40 rods is 200 meters.

In English the phrase "doing  at " is usually figurative.  It means that you're having an effect from a long ways away.  It usually means something is strong.

Obviously, whiskey can't kill someone 200 meters away.  But you can imagine a whiskey that strong.

Answer

In addition to what Marlon wrote:

https://simple.wikipedia.org/wiki/Rod_(unit)

https://en.wikipedia.org/wiki/Rod_(unit)

Answer

From forty +‎ rod, a measure of distance, suggesting whiskey so strong it can affect one from 200 meters away.