It seems so, according to the entry on pneumatic tubes in the wiki Dead Media Archive, although the wiki contributors acknowledge that there are "ghastly remnants" of the dead medium, including a limited rebirth in a hospital (sounds like something from Riget).
The Dead Media Archive is described as concerning "historical research into forgotten, obsolete, neglected or otherwise dead media technologies", qualities which do not seem to describe the pneumatic tube systems currently alive and well in institutions (and some homes!) all around the world.
Despite its eulogy style rendering of pneumatic tube systems, the dossier is very good, covering the origins of pneumatics in Ancient Greece, through to the hundreds of patents submitted for tube technology in the late 19th Century. Authors/editors ponder the difference between the telegraph and pneumatics, writing that "unlike the telegraph, which digitizes messages, the pneumatic letter retains analog meaning, which could range from your handwriting to the type of stationary you use".
For those interested, there is a fabulous list of resources at the end of the article too, with some important Scientific American papers, including one from 1873 entitled “Novel Mode of Locating Obstructions in Pneumatic Tubes”, which describes a method of isolating pneumatic tube obstructions utilising sound waves.
There are also great dossiers on other dead media, including those which I remember from childhood (paperdolls, mixed tapes and walkmans), from my university days (microfilm and credit card imprinters), to those which still seem to be hiding in my parents' cupboards (phonebooks). And there is one article about a dead media which I wish wasn't so dead - shorthand - which I think would be wonderful to know as an ethnographer!
See the full list of Dead Media Archive dossiers here.
Image from Dead Media Archive of Albert Brisbane's pneumatic tube patent. Brisbane is often credited for 'inventing' the pneumatic tube, although its origins are reported in the dossier as a "hodge-podge" of previous patents and improvements.
