What is interesting about the book is that, if I remember correctly, McKay was an actor, song writer, journalist, etc. He wasn't an economist by training, though there were few economists as we understand the word today. I believe his perspective was one of narrative or story of manias. Baruch, by the way, wrote the introduction to the edition issued in 1929.
Also, if you're interested, Galbraith (liberal economist) wrote a much shorter version called A SHort History of Financial Euphoria.
I found this short biography on the internet:
MACKAY, CHARLES (1814-1889), Scottish writer, was born at Perth, on the -27th of March 1814, and educated at the Caledonian Asylum, London, and in Brussels. In 1830, being then private secretary to a Belgian ironmaster, he began writing verses and articles for local newspapers. Returning to London, he devoted himself to literary and journalistic work, and was attached to the Morning Chronicle (1835-1844). He published Memoirs of Extraordinary Public Delusions (1841), and gradually made himself known as an industrious and prolific journalist. In 1844 he was made editor of the Glasgow Argus. His literary reputation was made by the publication in 1846 of a volume of verses, Voices from the Crowd, some of which were set to music by Henry Russell and became very popular. In 1848 Mackay returned to London and worked for the Illustrated London News, of which he became editor ~fl 1852. In it he published a number of songs, set to music by Sir Henry Bishop and Henry Russell, and in 1855 they were collected in a volume; they included the popular Cheer, Boys! Cheer! After his severance from the Illustrated London News, in 1859, Mackay started two unsuccessful periodicals, and acted as special correspondent for The Times in America during the Civil War. He edited A Thousand and One Gems of English Poetry (1867). Mackay died in London on the 24th of December 1889. Marie Corelli (q.v.) was his adopted daughter. His son, Eric Mackay (1851-1899), was known as a writer of verse, particularly by his Love Letters of a Violinist (1886).