In nature, he states halfway through the book, 'there are some experiences that literally alter the chemistry of your brain'.

These salts alter the chemistry of the water, allowing it to remain liquid at lower temperatures and pressures.

Control of the fuel/air balance can alter the exhaust gas chemistry toward either an oxidizing or a reducing mixture, and thus alter the chemistry of the material being processed.

Although their exteriors are subjected to intense solar radiation that can alter their chemistry, their interiors contain pristine material essentially untouched since the planetesimal was formed.

Sewage inflow into the lake has altered the chemistry and biology of the lake.