What did maxwell do to prove light was electromagnetic in nature and the concept of his displacement current

The objective of this presentation is to address two specific topics which are so fundamental in engineering electromagnetic education. These two topics are: how did Maxwell reached the conclusion that light was electromagnetic in nature and thereby revolutionizing the last century physics and the concept of displacement current. None of the textbooks on electromagnetics deal with these two important topics. The most interesting part that is often not recognized that Maxwell reached the conclusion light was electromagnetic in nature before he used the concept of displacement current to derive his 20 equations which were later converted to four by Hertz and Heaviside. Therefore, a point which we all must recognize that Maxwell did not reach the conclusion that light was electromagnetic in nature form his 20 equations which he published in 1864 and for which he lacked the boundary conditions to solve. In a letter to Faraday on 19 October 1861 Maxwell writes:.. I think we have now strong reason to believe whether my theory is a fact or not, that the lumineferous and the electromagnetic medium are one [1,2]. In the third part of his paper on Physical Lines of Force published in January 1862, Maxwell established a connection between the speed of light and the speed of propagation of waves in an etheral medium. It was also in this paper that Maxwell introduced the term displacement current which is now included in Ampère´s circuital law. Relating to that concept, the thinking is Maxwell introduced the displacement current while recognizing that there is an all pervading medium called ether. But nowadays we do not consider the existence of ether and so the point is should we then not modify the concept of displacement current? We explore the significance and the relevance of these two ideas in current electromagnetic education.