[wbarmy]

Darwin's 1871 letter to Joseph Hooker with his speculations on the spontaneous generation of life. This is where he talked about the small warm pond where some chemicals and light and heat and electricity combined to form the first stirrings of life. Exactly the scenario that Miller started out with.

[AndyTheBear]

OK thanks for the reference. I remembered the gist of his comments on the origin of life, but I did not remember enough specifics to get google to find it.