Question: Apart from the founder of the Exclusive Brethren, what is the name of the second person who was sent by the Plymouth Brethren to investigate the outbreak of supernatural gifts of the Holy Spirit in Scotland?

Context paragraphs:
Behind the Exclusive Brethren: Behind the Exclusive Brethren: Politics Persuasion and Persecution is a non-fiction book by journalist and author Michael Bachelard about the group Exclusive Brethren, focusing on the sect in Australia.  It was published in 2008 by Scribe Publications Pty Ltd.  Bachelard first became interested in the organisation while a journalist for "The Age", after finding out that prior to the 2007 Australian federal election the Exclusive Brethren organisation in Australia had close access to John Howard.  He spent two years researching the group, focusing on its history, influence in Australia, and ties to the Liberal Party of Australia and to Howard.  The book gives a historical background of the group's origins 200 years ago in Ireland under John Nelson Darby.  Since 2002, Bruce Hales served as the international leader and "Elect Vessel" of the organisation, which has 15,000 members in Australia and 43,000 total globally.  The author describes the beliefs and practices and doctrine of the organisation, including some of its more controversial methodology including excommunication of former members from their family still within the group.  Daniel Hales, brother of the organisation's worldwide leader Bruce Hales, described the book as part of a trend of what he said were lies told about his group by critics and disaffected former members.

Needed Truth Brethren: Needed Truth Brethren, as they are sometimes known, call themselves "“The Churches of God in the Fellowship of the Son of God, the Lord Jesus Christ"."  Although this is their official legal title, other Christians often classify them as a very conservative strain of the Plymouth Brethren, connexional in nature, and holding themselves separate from what they consider to be erroneous practices.  The designation "Needed Truth" was given to them by others based on the "Needed Truth" Magazine, which began to be distributed among the Open Brethren in 1888.  This magazine espoused what it considers a fresh understanding of biblical teaching of the proper constitution of the local church, principles of church government, and doctrinal subjects such as "The House of God, the Church of God, the Kingdom of God," and "the Body of Christ".  The magazine presented these views as being a return to fundamental New Testament principles which had been forgotten.  (The Plymouth Brethren movement as a whole had, from the beginning, seen itself as practicing a return to fundamental New Testament principles which denominational organizations had lost sight of.)

Benjamin Wills Newton: Benjamin Wills Newton, (12 December 1807 – 26 June 1899) was an English evangelist and author of Christian books.  He became the most notable leader of the church in Plymouth after which the Plymouth Brethren were named.  Although he had been a close friend of John Nelson Darby, they began to clash on matters of church doctrine and practice which led to the 1848 split of the brethren movement into the Open Brethren and Exclusive Brethren and Newton's withdrawal.

Plymouth Brethren Christian Church: The Plymouth Brethren Christian Church (PBCC) is a Protestant church, often known as Exclusive Brethren or Raven-Taylor-Hales Brethren.  These Brethren hold an uncompromising 'separatist' doctrine and their practice has steadily evolved differently from other Plymouth Brethren groups and also from mainstream Christianity.  In a radical departure from traditional Plymouth Brethren rejection of a clerical hierarchy, the PBCC has evolved into a tightly-controlled hierarchical organization dominated by one person known as the Elect Vessel or the Man of God.  The current Elect Vessel is Bruce Hales of Australia.  Most media reporting of "Exclusive Brethren" relates only to the Plymouth Brethren Christian Church although other branches exist.

Christian Brethren in Egypt: The Christian Brethren are a denomination of Protestant Christianity in Egypt.  They are related to the Exclusive Brethren tradition, even though the "Christian Brethren" label is internationally used more often by Open rather than Exclusive Brethren.

John Nelson Darby: John Nelson Darby (18 November 1800 – 29 April 1882) was an Anglo-Irish Bible teacher, one of the influential figures among the original Plymouth Brethren and the founder of the Exclusive Brethren.  He is considered to be the father of modern Dispensationalism and Futurism.  Pre-tribulation rapture theology was popularized extensively in the 1830s by John Nelson Darby and the Plymouth Brethren, and further popularized in the United States in the early 20th century by the wide circulation of the Scofield Reference Bible.

Little Flock hymnbook: The Little Flock hymnbook is in common use amongst Exclusive Brethren in various editions which nevertheless derive from a common source.  It exists in almost as many variations and editions as there are distinct groups of Exclusive Brethren.

Brethren (religious group): Brethren is a name adopted by a wide range of mainly Christian religious groups throughout history which do not necessarily share historical roots, including some of the earliest primitive churches , like the Brethren of the Free Spirit.  The Paulicians, the Bogomils, the Schwarzenau Brethren and Anabaptist groups, the Moravian Brethren, and the Plymouth Brethren, among many others as part of the historical Brethren Movement.  See "The Pilgrim Church" by Edmund Hamer Broadbent.

Margaret MacDonald (visionary): Margaret MacDonald was born in 1815 in Port Glasgow, Scotland and died around 1840.  She lived with her two older brothers, James and George, both of whom ran a shipping business.  Beginning in 1826 and through 1829, a few preachers in Scotland emphasized that the world's problems could only be addressed through an outbreak of supernatural gifts from the Holy Spirit.  In response, Isabella and Mary Campbell of the parish of Rosneath manifested charismatic experiences such as speaking in tongues.  Around 1830, miraculous healings were reported through James Campbell, first of his sister Margaret MacDonald and then of Mary Campbell (through James's letter to Mary).  Shortly thereafter, James and George MacDonald manifested the speaking and interpretations of tongues, and soon others followed suit in prayer meetings.  These charismatic experiences garnered major national attention.  Many came to see and investigate these events.  Some, such as Edward Irving and Henry Drummond, regarded these events as genuine displays from the Holy Spirit.  Others, including John Nelson Darby and Benjamin Wills Newton, whom the Plymouth Brethren sent on their behalf to investigate, came to the conclusion that these displays were demonic.

Exclusive Brethren: The Exclusive Brethren are a subset of the Christian evangelical movement generally described as the Plymouth Brethren.  They are distinguished from the Open Brethren from whom they separated in 1848.

Supporting paragraphs: Margaret MacDonald (visionary) John Nelson Darby
Answer: Benjamin Wills Newton