Drops pretend to be burned in the rain

When setting fire with a flintlock to a drop of any item in the rain, that drop is invisible, but it is still there.

How to reproduce

1. Make it rain;

2. Drop any item on the ground in an uncovered area;

3. Take a flint and steel and set the drop on fire;

4. To make sure the item is still there, go to where it is and pick it up.