Leak provides a survey of Islam, and its relations to Christendom. His work involves the history, distribution, doctrines, and practice of Islam, and argues that the utter unlikeness of Allah is equivalent to agnosticism.
his work contains a discussion between Carl Heinrich Cornilland Bernhard Stade on the meaning of Jeremiah as "a prophet unto [the] nations" (1:5) in the context of the first chapter.
This volume provides an introduction, study, and notes on the Arabic text about the Patriarchs of the Church of the East, edited under the title Maris Amri et Slibae De Patriarchibus Nestorianorum Commentaria by H. Gismondi.