The original cast for these bat lights is from the Mackenzie House. The Nathan Lob House (726 NW 22nd) is also has one that quite possibly is a replica. The original lamp at the Mackenzie House was a interior gas lamp. In Scottish folklore the bat is associated with witches, dark magic, sorcery and necromancy. The bat in this piece of art is the messenger between witches and the devil. Satan is often depicted in art with bat-like wings where as angles have bird-like wings.
The snake, on the other hand, is a symbol of medicine. This single snake on a rod is not the common medical symbol–the caduceus, which features two, snakes a stick and wings. This is linked to the Greek God Hermes–the rod had been a gift from Apollo and the snakes were battling and the rod was used to separate them. Doctors traveled and the walking stick was associated with itinerate medical men and Hermes the winged god was their patron saint.
Dr. Mackenzie was a Scot and a prominent physician. The lamp in the entry of his house, (615 NW 20th /2023 NW Hoyt) with the snake over the bat, depicts the triumph of medicine over the occult. A single snake on a rod it is the asklepian (the Rod of Asclepius son of Apollo). The snake that’s wrapped around the rod may symbolize rejuvenation and held by the deity of medicine and healing.