Nitrite is present at trace levels in soil, natural waters, plant and animal tissues, and fertilizer.

Furthermore, the fact that potassium nitrite is highly soluble in water makes the solid difficult to recover.

Therefore, he decided to try the effect on a patient of inhaling amyl nitrite, a recently synthesized compound and one that his colleague had shown lowered blood pressure in animals.

Pain associated with an anginal attack disappeared rapidly, and the effect lasted for several minutes, generally long enough for the patient to recover by resting.

For a time, amyl nitrite was the favored treatment for angina, but due to its volatility, it was replaced by chemically related compounds that had the same effect.

[2] The effect of potassium nitrite on the nervous system, brain, spinal cord, pulse, arterial blood pressure, and respiration of healthy human volunteers was noted, as was the variability between individuals.

The most significant observation was that even a small dose of <0.5 grains (≈30 mg) given by mouth caused, at first, an increase in arterial blood pressure, followed by a moderate decrease.

This facilitates more efficient electronic transfer capabilities and increases the kinetic energy of the oxidation reaction, making nitrite a more reactive oxyanion than nitrate.