Compounds made from barium can be exceptionally toxic. In countries with not-so-strict regulations, barium carbonate is used as a rat poison. The effects are so horrid that you almost feel bad for the pests as it basically gives them an accelerated form of Parkinson’s disease. Within minutes of ingestion their guts are wrecked, their muscles stop responding to the brain and begin twitching of their own volition, their kidneys are shot, then their heartbeats become irregular and several other Bad Things before the merciful end comes from respiratory failure. Medical literature speaks of cases where the white powder was mistaken for flour and… well, let’s move on.

On the other hand each and every day thousands of people in hospitals all over the world are made to drink up Slurpee-sized cups of a vile concoction of barium sulphate (tastes exactly what you would think a liquified chalk smoothie would taste like) prior to getting an abdominal x-ray. Vile but harmless. The offending chemical passes through uneventfully. Well, except for the retching and the memories that will never go away.

So how come? Well, it all hinges on how the metal gets into an organism and what it does once it’s inside. Barium carbonate is water soluble while the sulphate isn’t. Big difference. While the sulphate is indegistible, the gastric juices attack the carbonate and turn it into a chloride which easily passes through intestine walls. Once in the bloodstream barium ions ravage the body’s stores of potassium rapidly depleting this essential electrolyte. This in turn causes all the cascade of nerve and muscle problems described above.

Metallic barium like in this ampule is not a health concern. If the glass were to break - by some unspeakable catastrophe - and your beautiful specimen exposed nothing much would happen even if you were to pick it up with your bare hands. Holding it for a long time might irritate your skin (a chemical burn) but after you washed your hands and said good-bye to your expensive collectible that would be the end of it. Where it does become a much bigger danger is if a piece were to be eaten as, again, the acids in your stomach would make short work of it and turn it into a potentially lethal poison. For this reason, make sure that all of your element samples are well out of reach of little kids.