What is meant by "instant " and "ult" in death notices in the 1800's?

Question

it is always after the date doesn't look like it is part of "causes"

Answer 1

It should be preceded by a number, right?

So if it says 4th instant, that means the 4th of the same month. 4th ult. means the 4th of the previous month.

Answer 2

I'm guessing "instant" death is like having an accident or being murdered and dying right away.

"ult" is probably for "ultimately" which is probably a long drawn out illness, like cancer, or having an accident and not dying instantly.  Like, Bob was mauled by a bear which ultimately caused his death.  Or, Bob was mauled by a bear and died instantly.

Answer 3

Instant means this week or this month (comes from "instanter" which is a legal term for immediate)

Ultimo means last. So depending on the context it's either last week (Tuesday ult) or last month (25th ultimo). It was mostly an East Coast and Midwestern thing. Most of the country didn't use the terms frequently.