Dr. Brown's Cel-Ray Tonic was originally one of those "snakeoil tonics" that supposedly cured "EVERYTHING", that was sold by traveling "medicine men" shows on wheels. It may or may not have been carbonated at that time ( I really don't know and don't remember ever reading about that part of its history ), but not to long afterwards became a very popular drink, like Coke, Dr. Pepper, etc. and sold in drugstore soda fountains as well as in Deli's.
I love the stuff, have very fond childhood memories of it, and for those who don't like it, here's a hint...it's best when served VERY cold and if possible, with ice cubs in it.