We now have an excellent, up-to-date description of modern charlatanism, Paul Offit's Do You Believe in Magic?, HarperCollins, 2013.
The early chapters of the book give a rundown of some of the big names of 20th century charlatanism, among whom the name of Linus Pauling may be the most interesting. After a most distinguished career in science, including a Nobel prize in chemistry, Pauling turned his back on science and began advocating cultic nostrums. Apparently the turn occurred when he was 65 years old, in 1966, and the reader is left wondering whether the cause was some sort of senescence. Offit does not mention this, but Pauing gave an earlier indication of oddness, when he participated in Communist fellow-travelling in 1948 by endorsing the Henry Wallace candidacy for President, and again a year later, when he participated in the Communisty-organized "Peace Conference" at the Waldorf-Astoria Hotel in New York.