I completely forgot about this after talking to Roy a while back. Sorry.
On to the subject:
This was from the journals of Father Juan (Johann) Nentvig SJ (Jesuit) entitled "Rudo Ensayo" written in 1764. You can read the entire book here:In the vicinity of Oputo there are many silver mines which are abandoned because of the many outrages committed by the Apaches, such as what happened at Nori, three leagues north of Oputo, and at San Juan del Río, nine leagues beyond in the same direction. Numerous veins with good metal showings have been located southeast, southwest, and northwest of Oputo at distances of from four to fifteen leagues. The color of the mass as well as the night flashes visible during the rainy season are indicative of mineral deposits, but the utter poverty of the residents and the constant enemy danger hamper their being worked. Similar flashes occur in the environs of Huásabas, and the deposits remain untouched for the same reasons.
The phenomenons of light flashes, mystery lights, and different colored mists have been staples of Miners' knowledge since the early Middle Ages. Cornish Miners often (to this day) refer to "Blue Mists" that hover thickly over underground veins.
The earliest book devoted to the Mining Arts was "Das Bergbuchlein" written in 1505 in Germany. In it, the author describes a phenomenon called "Witterung." In different books Witterung means slightly different things (Glowing Mists, Colored Mists, Earth Exhalations, etc).
Boyle 1661 "Sceptical Chymist"Whether mists used to rise from grounds stored with minerals? Whether the place more than ordinarily subject to Thunder and Lightning.........as likewise to nocturnal lights and fiery meteors
Glauber 1750The exhalations were known as "Witterung" and could be seen rising above vein outcrops. Glauber considered they gave rise to a blue flame, a sure indication of rich ore deposits.
I had heard about these stories for a long time, but didn't put much stock in them, until I met an old timer who makes the rounds to Stanton (Rich Hill), Rye Patch, etc. He actually had pictures of the lights. He sets up his video camera about dusk and leaves it running till after dark. He collects it and reviews the video. If he finds something, he gets a frame from the video and prints it. I have to say that I was impressed.
The theory is that gasses develop from the different minerals associated with the different types of ore (like arsenic in gold ore). During periods of high humidity/rain, as the sun goes down, the temps radically change. The pressure differential is so great that the gasses vent to the atmosphere and phosphoresce. Different minerals/ores give off different colored lights. That is the theory anyway.
Anybody have anything else to share? Pics maybe?