Generally speaking, yes but ... It depends on what the substance is and what you want to separate. If the substance is a mixture of sugar and water then the water can be evaporated off and the sugar...
I am assuming that you mean fresh, straight out of the cow milK? Simple separation can be done by letting the cream rise to the top and skimming it off. The milk will still have some cream content...
What do you mean by 'parts'? Are you talking about the social equality or something?well, if it is, then, everyone is treated the same way as others. Atleast that is what I could see. If you are...