Henry Drummond (1851 -1897) was a Scottish evangelist, writer and lecturer. In 1877 he became lecturer on natural science in the Free Church College, which enabled him to combine all the pursuits for which he felt a vocation. His studies resulted in his writing Natural Law in the Spiritual World, the argument of which is that the scientific principle of continuity extends from the physical world to the spiritual. Before the book was published in 1883,...