Leaf skeleton

I spotted this leaf skeleton on my walk today. I was impressed at how complete it is. I didn't stop for coffee in town as my friends weren't there. I returned home to clean a clock and settle down to an afternoon of rugby. There was a bit of a panic this morning as visitors to our house in France switched on the boiler without turning on the water.  I hope it is a closed system and it wont cause any problem.  I think most old fashioned systems are.