CHEMISTRY - WHAT defines it?

Since sweet lullaby and odd were talking about chemistry, I'd like to give my take on it too..

Does Chemistry equate to heart beating very fasT? Eyes rolling or blushing when the person of desire is nearby? Sweaty palms, dry throat? Shuddering or stuttering speech when talking to him/her? If any of these strike you, perhaps, there is 'chemistry' in the relation?

Does chemistry signify deep connection with a person? that perhaps this is THE ONE? I am not sure. I dont think anyone has the answers. All I can say is that chemistry does wear off..

I too experienced such potent chemistry before. I too went with my heart on some of these occasions.Looking at the magnitude I felt from the chemistry, you'd think it'd last forever.. At last it didnt. When i saw the person I had so much 'chemistry;' with some years later, I found myself wondering why did I even fall in love in the first place? Whatever chemistry I felt I had had gone. This happened a couple more times.. which leads me to the conclusion... chemistry is the intial attraction, growing love in the relationship is the key.. chemistry can die off, yet love can grow stronger ... (or can grow weaker with neglect too)

I dont know about whether chemistry is art or science. I just know this.. its transient and it wears off.. so gotta keep 'feeding' it? what can 'feed the chemistry'? I like to think its love.. but I think even love can also grow weak? So what feeds the 'chemistry' in couples? I can only think of one word.. (this is just my own opinion.. maybe I am too one dimensional with this 'answer').. that is

COMMITMENT

Imagine.. you have chemistry with a person.. heart beats, blush blush.. but no commitment, no agreeing to stay together..no consideration for each other to want to commit and make something together.. its purely a rush of emotions.. do you think this will last? Human Beings been famous for a whole gamut of emotions.. can such fleeting feelings be an accurate barometer of soul connection? Is it just raging hormones or pure lust? Can it mean something deeper?
Or it will just be yet another forgotten memory ?