The conversation between human and AI assistant.
[|Human|] From the passage provided, extract the name of the person who first proposed and tested the law of conservation of energy.
[|AI|] Ãmilie du ChÃ¢telet first proposed and tested the law of conservation of energy.
[|Human|] 
From the passage provided, extract the name of the person who first proposed and tested the law of conservation of energy.