""The Efficacy of Prayer: The Donnellan Lectures for the Year 1877"" is a book written by John Hewitt Jellett, published in 1878. The book is a collection of lectures delivered by the author on the topic of prayer and its effectiveness. Jellett explores the nature of prayer, its purpose, and the different forms it can take. He also examines the relationship between prayer and God, and how prayer can be used to bring about change in the world. The...