Ground glass as a poison

I happened to catch 60 Minutes this Sunday and was saddened to see the poisoning of lions and tigers by a plant pesticide called Furadan solely for the sake of saving the lives of cattle. Now I see the manufacturer is to stop making it.

It reminded me of a story my mother told me, that when she was a little girl, they had a rather obnoxious neighbor who hated all the neighborhood kids. Her father brought her a new puppy which she dearly loved and cared for but which the mean neighbor seemed to take a particular disliking.

The puppy was only allowed outside the yard with my mom (as a little girl) and otherwise stayed in the back and side yards which had an L-shaped fence.

My mom said after about a year with the puppy, one day she came home and found him dead with blood and foam coming from his mouth. She was very upset for several weeks following.

Her father took the body to the local vet where the stomach was cut open and inside he found a ball of hamburger meat which he suspected had been mixed with ground glass. My mom said the vet told them the ground glass had caused massive internal bleeding resulting in death. In an old book I found mention of ground glass thought to be a poison when ingested;

"Sir Thomas Browne experimented with it on dogs and tells us that he gave 'unto dogs above a dram thereof subtilely powdered in butter and paste, without any visible disturbance.' Nevertheless he tells us that 'glass grossly or coarsely powdered is mortally noxious, and effectually used by some to destroy mice and rats.'

This idea that powdered glass is an efficient poison for rats and mice is quite prevalent, but it has been proved by recent experiments made under the direction of the United States Department of Agriculture that glass, whether coarsely or finely powdered, has no ill effects upon rats.

Rats were fed for some time on food mixed with the glass and they did not seem to be injured by it. And when examined after being killed, the alimentary canal was found to be in normal condition. So that we may safely relegate the belief in powdered glass as a poison to the list of popular fallacies."

I did a check on the net and found this very good article about it at Snopes.