The book consists five chapters. Chapter1 provides an introduction to the concepts relevant to the book such as Newtonian fluid, porous medium, heat and mass transfer, Soret and Dufour effects, radiation and chemical reaction effects. A review of the pertinent literature is also presented. Chapters 2, 3 and 4 deal with natural convection heat and mass transfer along a vertical plate embedded in an electrically conducting doubly stratified Newtonian fluid saturated Brinkman porous medium with prescribed wall conditions on temperature and concentration. In Chapter 5, summary of the contents of the previous chapters is presented, indicating scope for further work.