The .22 Short has long since been overshadowed by its bigger brothers — (in order from smallest to largest) the .22 Long, the .22 Long Rifle, the .22 Winchester Magnum Rimfire, the 5mm Remington Magnum Rimfire and the latest in rimfire cartridges, the .17 Hornady Magnum Rimfire.
The .22 Short was the very first small caliber rimfire cartridge, developed around 1857. It was practical, even for its diminutive size (being about a half inch long), for taking care of barnyard pests, such as rats and pigeons, and paving the way for target shooting that could be had cheap. Though the weight of the .223" caliber slug has changed over time, it is now settled on 29 grains with a velocity somewhere near 1050 feet per second (one must understand that there is variation, shell to shell, lot to lot, of any kind of ammunition). To put this in perspective, some of the more powerful air rifles are capable of giving similar results, today.
Eventually, the .22 Long (developed in 1871) and .22 Long Rifle (developed in 1887) overshadowed the diminutive cartridge because they could offer more velocity, and by extension, killing power. It wasn't long before the .22 Long Rifle became the de facto size and shape that all other .22 caliber rimfire cartridges became somewhat obsolete.
While it is difficult to find the .22 Short today, they are still available. Winchester, Remington and CCI all have at least one offering in production. However, since there is not enough demand for these cartridges, they are typically more costly than the now ubiquitous .22 Long Rifle; this is interesting, as it was the .22 Short that was the cheapest rimfire cartridge for many, many years.
One can use a .22 Short in a firearm designed for the longer cartridges of the .22 Long and .22 Long Rifle. However, unless the firearm is a single shot, bolt action rifle, feeding problems may occur in tubular or magazine fed rifles and pistols.