Odd fire extingisher

Last week, while in my attic to string the speaker wires, I took a photo of one of the odd fire extinguishers I found on the attic beams.

At least I think they are fire extinguishers as I can think of no other reason for them to be hanging in the attic.  When I look through the clear top I see a liquid inside the container.

Actually I looked these containers over in depth years ago back when I put extra insulation in the attic.  So I can't really answer (remember) right now whether these containers are glass or plastic or ceramic or some other combination.

I did a little research on Google about "glass fire extinguishers"  and I found out three things:

1. They are collectible and worth money,
2. Some versions are called fire grenades, and
3. They are very dangerous.

From Wikipedia:   (http://en.wikipedia.org/wiki/Fire_extinguisher)

Another type of carbon-tetrachloride extinguisher was the Fire grenade. This consisted of a glass sphere filled with CTC, that was intended to be hurled at the base of a fire (early ones used salt-water, but CTC was more effective). Carbon tetrachloride was suitable for liquid and electrical fires and the extinguisers were fitted to motor vehicles. Carbon-tetrachloride extinguishers were withdrawn in the 1950s because of the chemical's toxicity–exposure to high concentrations damages the nervous system and internal organs. Additionally, when used on a fire, the heat can convert CTC to Phosgene gas,formerly used as a chemical weapon.

Another article on the fire grenades is found here:  http://www.thegavel.net/grenade.html

Other articles mentioned how carbon-tetrachloride robs the fire of oxygen.  That is both good and bad.  The bad is if you are nearby and need oxygen also.

For now I will leave them be.  Initially I thought they were neat.  Now that I learned more about them I would like to remove them but I don't want the risk of accidentally breaking them.   They have remained intact in the attic for 50 to 70 years - the range between when the house was built and when it appears these type of fire extinguishers were taken off the market (late 1950s)

Now... if someone wants to buy them and remove them, I would be fine with that.

Also, in the photo you can see how old my attic is.  Instead of plywood sheets for the roof, the builders used 1 inch boards.  And why the long bamboo pole is in the attic... who knows!