Tracer mixture
July 27, 1926 | Application filed October 22, 1923 | US Patent 1,593,721 | Source

https://patentimages.storage.googleapis.com/83/0a/9b/58090c7e76ef3a/US1593721.pdf
“A mixture such as forms-the subject of my invention will consist essentially of a salt of an alkali earth metal having a characteristic color of burning, a second salt acting as an oxidizing agent but which also preferably though not necessarily will have the same characteristic color of burning, a suitable fuel and a binder. To these ingredients, if it is desired to increase the brilliancy of the flame, may be added suitable oxidizing compounds.”