Histamine is a substance that is released by cells in response to injury,
infections, stings and stuff that cause allergic responses, such as pollen.
Histamine causes dilation of blood vessels and swelling due to
accumulation of fluid in the tissues. People sometimes take antihistamine
drugs to counteract the effects of histamine. A sample of histamine having
a mass of 0.367 g is composed of 0.190 g of carbon, 0.031 g of hydrogen
and 0.146 g of nitrogen. What is its empirical formula?