I could scarcely believe my eyes when I read the above headline on the BBC site. It's about a man who tried to poison his estranged wife by lacing her tea with mercury.
When you read the detail, it's clear that he used elemental mercury, ie the sort in thermometers. Mercury is the only metal that is liquid at normal temperatures. How do we know it was elemental mercury? See the reference to little "ball bearings" at the bottom of the tea cup.
Fortunately for the lady, her estranged husband was ignorant of chemical toxicology. Liquid mercury passes through the body largely unchanged, which would explain why her blood mercury levels were not raised, and why she appears - so they say- to have suffered no lasting ill effects - although she reportedly had symptoms of poisoning initially.
The real hazard with mercury comes from spillages. Mercury has an appreciable vapour pressure, and it's the vapour, when inhaled, which is highly toxic. Laboratories are required to have special decontamination kits to deal with mercury spills. They used to contain elemental sulphur to which the miniature silvery globules stick. Whether they still do or not, I couldn't say.
Mercury salts and other compounds are also highly toxic, although one would probably be doubled up with pain very quickly if these were ingested.
OK, so the guy was ignorant, but the intent was still there. Why should his sentence have been so lenient? The man tried to poison his wife - a despicable act - especially as it exploits intimacy and trust ("care for a cuppa, my dear?"). He wasn't trying to kill her, the court was told - but simply make her dependent. He just wanted her back, under the same roof, grateful to him as a "carer" to a bed-ridden wife. Oh well, that's OK then...