The villains of this story belong to a group called the Camorra. This group actually existed in the past and may have been a forerunner of the modern day Mafia.
Prince Gio - played by Peter Mark Richman - is described as being an expert in gung fu, a Chinese martial art not well known to American audiences at the time that this show was first aired. Six years later, in 1971, Richman co-starred on the series Longstreet, which featured real-life gung fu master Bruce Lee among its cast.
As usual, Artie's invention is several decades ahead of its time. His "crying gas" predicts the development of tear gas, which was first used by the French military in 1914 during World War I.
Another commenter correctly observed that: "After Jim says "they're gone" in the opening scene, Artemus responds with 2-3 words spoken softly, but nothing is heard." Artemus' inaudible words were "So is she". (She had just died.)