
1) Book about Christianity
Found on
https://www.crosswordclues.com/clue/gangraena

Gangraena is a book by Thomas Edwards, published in 1646. A notorious work of `heresiography`, i.e. the description in detail of heresy, it appeared the year after Ephraim Pagitt`s Heresiography. These two books attempted to catalogue the fissiparous Protestant congregations of the time, in England particularly, into recognised sects or beliefs......
Found on
http://en.wikipedia.org/wiki/Gangraena
No exact match found.