MERCURY very versatile stuff, I still use it to remove lead fouling from barrels.
These two items run on it.

[Linked Image from i.imgur.com]

The Hipp Regulator clock has fifteen pounds of Mercury in the Pendulum Weight. The Fortin Barometer has eight pounds of mercury. Any leakage from either would probably cause an environmental emergency maybe a disaster in these times.
Well we all have to die of something so I am now past caring.

On an other not so good for health is Radium in the photograph is a Victorian Radium Glass bowl. It looks that amber colour in the house, it turns to that greenish colour in ultra violet light in the other photograph.

[Linked Image from i.imgur.com]

[Linked Image from i.imgur.com]

I wont go on to the miles of Lead water pipes here.

The only lessons in my life I truly did learn from where the ones I paid for!