The term Scientology was apparently first coined in this book by Allen Upward (1863-1926), written in 1901, five decades before L. Ron Hubbard founded the belief system of the same name. It appears four times as a noun and once as an adjective (on p. 119, p. 139, p. 149 and p. 156).
Some opponents of Scientology have implied that this indicates that Hubbard plagiarized the word. However, I'm not aware of any evidence that Hubbard knew of this fairly obscure book. And the philosophy which Upward expounds in The New Word has nothing to do with any of the ideas of the latter-day Scientologists, as far as I can tell.
In fact, Upward uses it here as a disparaging term, to indicate a blind, unthinking acceptance of scientific doctrine. Nor is the 'New Word' of the title Scientology. Rather, the word here is Idealist, drawn from Alfred Nobels' will, the starting point for Upward's essay, and as Upward shows, a difficult concept to pin down.
Upward, who here claims to be a philologist, is critical of Latin and Greek neologisms, while not hesitating to invent some new words of his own besides 'Scientology': 'verihood,' 'katasynthetic,' 'interplode.' He uses a children's book about science to deconstruct some of the vaguer scientific concepts of the day, particularly the behavior of gas molecules and the all-pervading ether. Ironically, an obscure Swiss patent clerk named Einstein demolished these parts of 19th century physics in 1906, shortly before this book finally saw print, making Upward's critique a bit moot.
Intensely critical of everything and often uproariously funny, Upward's book is enjoyable reading in its own right, even if it is not exactly the Nobel prize material which he hoped for. He was apparently as obsessed with the Nobel prize as this book intimates. As a tragic footnote, Upward shot himself in November, 1926, upon learning that George Bernard Shaw had won the Nobel Prize for Literature.
Production notes: The New Word was originally written in 1901, and first published in 1908 in London. The copytext used to create this etext was a 1910 American reprint, which has a short postscript. Otherwise it is presumably identical to the first edition. This book is long out of print and difficult to find used. The copytext was obtained by interlibrary loan from Santa Clara University, and is autographed by Upward on the front end papers.