Antoine-Laurent de Lavoisier. Pronounced la-vwa-ZYAY. I looked it up to make sure I was right. You never can tell with French, there might have been an apostrophe after the L. It's the carbon dioxide level in your blood that triggers the "out of breath" feeling. (And don't ask me how that happens. Please Register or Log in to view the hidden image!) This is why carbon monoxide is deadly. It takes up the spaces on your blood cells that would normally go to carbon dioxide, yet it doesn't trigger the out-of-breath feeling, so you just lose consciousness without realizing that you need to breathe. This will happen even if you're removed from the space with the carbon monoxide in the air and the carbon dioxide level in your lungs returns to normal. This is also the mode of asphyxiation at high altitude without a pressurized environment. There is so little oxygen in the rarefied air, that your respiration does not produce enough carbon dioxide to make your blood "feel" out of breath. You have to force yourself to breathe consciously, and sooner or later you'll forget.