Don’t you know that Michael Faraday wrote about nudists in his Experimental Researches in Electricity (The 1855 Edition)? But, may be you know that nudists were mentioned in Niles’ weekly register (original dated 1815), containing political, historical, geographical, scientifical, statistical, economical, and biographical documents, essays and facts of the proudest period in the history of the republic? At least, Google Books is trying to convince us in that.
After that, you wouldn’t be surprised meeting “nudists” in Прибавленіе к руской исторіи Сергѣя Глинки (Addition to the Russian history by Sergey Glinka) that appeared in 1818, in Legendary Greece by George Grote (1900), or in American almanac and repository of useful knowledge (1835).
Everyone can make sure that 19th-century and even earlier (see, for instance, Auslegung der Episteln by Martin Luther, 1528) editions are crowded with mistakenly recognized “nudists” that may be found in dozens of books on different subjects.
The problem, of course, is with OCR Software used by Google in order to convert books and documents into electronic files. I think, words in databases of OCR systems must contain some kind of time and subject tags, to be sure that iPods or soccer wouldn’t arise in some ancient texts. On the other hand, such popularity of “nudists” in word database may indicate the popularity of the word (and activity described by this word) within society. 🙂
P.S. I’m a big fan of Google Books and believe that Google is doing a great job opening access to rare and unique books.