I read that post Graham and found it very enlightening. I'd have to go into his specific alchemical beliefs more, but I'm not sure it changes my primary point that alchemy was the respected science of the time and it was based on empirical evidence of the four attributes of all things: hot, cold, dry, moist. That belief in the nature of things led to the rational idea that these could be rearranged to produce noble metals. Did Newton subscribe to the basic idea of those four attributes?