How do I differentiate between semen (mani) and pre-seminal fluid (madhy), is it by smell?

Semen exits with a gush and force, a thick, white, viscous fluid, its smell resembling that of palm spathe or dough, and it is followed by a weakening of desire. It is pure and necessitates ghusl (ritual bath). As for pre-seminal fluid (madhy), it exits without a gush, a thin, clear, sticky fluid with no smell, and it is not followed by a weakening of desire. It is impure and necessitates wudu' (ablution) and washing the penis and testicles, and sprinkling water on whatever parts of the body and clothes it has touched. As for prostatic fluid (wady), it is a thick, white fluid that exits after urination. It is impure and necessitates wudu'. The presence of even one of the characteristics of semen is sufficient to deem it semen.