> > > One thing they found was a hand grenade
> > that he had kept since World War I. This guy
> > did NOT like to throw things away.
> >
> > So did your grandparents keep it, or throw it
> > away?
> >
> > Gri"we've got an 80-year old hand grenade,
> > and we're NOT AFRAID TO USE IT!"shny
>
> They called the Bomb Squad, who took it away.
>
> -Eric Sleator
> Fri 22 Nov A.D. 2002

Big mistake. Most of those grednades that were brought home were practice grenades that contain no powder. I don't know about WWI grenades, but in WWII and later, the practice grenades were painted with blue paint. Most of it wore off, but you could always find traces of it. A practice grenade from WWI would be a valuable antique, but the bomb squad probably wouldn't mention that. Still, if you aren't sure, you need to play it safe.

I remember one hot day in Oklahoma a long time ago, when I chanced upon a live artillery shell.
I was out there working for my uncle* and I sat down on the edge of a gully to rest. Right next to me, less than half buried in the ground was a 155mm shell complete with fuse and full of TNT. It was a dud that had landed without exploding many years before, and had eroded out of the ground. I don't know how long it had been exposed to the Oklahoma sun, but I know that tends to make even a dud unstable as all get out. I moved carefully away.
Howard
*Uncle Sam