Source: all over the Web. Seems original may have been “Every professional language”, rather than profession itself.
The "Conspiracy against the laity" quote is from George Bernard Shaw's preface to "The Doctor's Dilemma" He also accused the profession of having "an ignoble character" His dad was a physician, and the characters in Doctor's Dilemma are well observed and still very recognisable.
http://www.drrant.net/2007/06/and-devil-is-being-tosser-too.html