Lorentz's electromagnetic mass: a clue for unification?
  We review in the present article the conjecture of electromagnetic mass by Lorentz. The philosophical perspectives and historical accounts of this idea are described, especially, in the light of Einstein's special relativistic formula {E = mc^2}. It is shown that the Lorentz's electromagnetic mass model has taken various shapes through its journey and the goal is not yet reached. 
Saibal Ray