OK guys,,,, The German Company Weihrauch who makes a lot of the good Spring Piston air guns once produced a version of the HW35 in .22 cal. know as the Barakuda.
http://www.pyramydair.com/blog/2006/...l54-ether.html
It was a normal HW35 in .22 cal. with an attachment that dispensed a drop of ether behind the pellet just before you fired the gun.
It produced .22 LR velocities from a gun that normally had 580 fps velocities in .22 cal.
So the short answer to the OP's question is . It was done in the late 60's early 70's.
They used Ether as the propellant due to its low flash point. IE the compression of the piston in the gun easily ignited the ether.
On a side note: There are Diesel Model Airplane Engines that have been around from the beginning. In fact most European Model Airplane Engines are Diesels.
They run on a fuel made of 33% kerosene, 33% Ether, and 33% Castor oil.+ some traces of some additives I have forgotten.
These engines are compression ignition engines and the combustion chamber is adjustable to cope with ignition timing and actual compression. They end up running in the 9:1 Comp ratio regime due to the inclusion of Ether in the fuel which lowers the flash point of the fuel mixture.
These engines are about 1.5 times the horsepower of a similar displacement Alcohol/Nitro fueled Glow Ignition style engine common here in the US. This mainly due to the higher density of the Kerosene. The ether is in there to start the fire easier.
This is also the reason why diesel engines produce more power than gas motors. Normal gasoline is around 10,000 BTU's per pound. Diesel fuel is 18,000 BTU/LB. Kerosene is even higher and that's why they use it as Jet fuel.
It is easy to see this if you look at the structure of the individual molecules of fuel. Natural Gas is CH4 "Methane" that is one carbon atom with 4 hydrogen atoms surrounding it. Gasoline is 6,7,or8 carbons lined up IE: Sextane, Septane /Heptane, Octane, with 14, 16 or 18 H's around. Diesel is 12,13,14 carbons and 26,28,30 H's and kerosene is 20-40 C's in a row, with 42- 82 H's !
It is easier to see how these denser fuels have more poop. This is why 75% of the cars in Europe are diesel powered. VW Jetta wagons have a 2.0 L engine that produces 140HP and gets 42+ mpg. A new 2.8L BMW engine in the 3 series cars is 280HP and yields 45 mpg. Looking at one of those later today or tomorrow.
This is why I own diesel powered vehicles.
Randy