Off-topic, but since you mentioned googling for more info and failing to find the given link, here are a couple of other links I thought you would find interesting:
1. The Amazon page for the book "An Underground Education", mentioned as the source in the given link:
http://www.amazon.com/exec/obidos/ASIN/0385483767

2. The Wikipedia page on Robert Hooke. There's a section at the bottom mentioning Newton and the famous quotation:
http://en.wikipedia.org/wiki/Robert_Hooke