Re: Who discovered dry ice?

Lavoisier and Priestly were involved with carbon dioxide earlier, but did not 
make dry ice.

According to this excerpt 
from a book by Charles Sheffield,
In 1834, Charles Saint-Ange Thilorier of  produced carbon dioxide snow 
(dry ice, melting point -78.50C) for the first time using gas expansion. 

A hundred years later, Dry ice found one of its most popular uses:  
keeping ice cream cold.

Here is a nice website with experiments involving dry ice:
Dry Ice Information