Black Beauty samples

Black Beauty and Maitland Samples. Approximately three miles northwest of Walsenburg, Colo., coal beds of the Vermejo formation are cut by a northeast-trending. nearly vertical dike which is approximately 25 feet thick. Fortunately, at this locality two coal mines have operated—one on either side of the dike. Both mines have been developed by drifting in from the outcrop of the seam. The Black Beauty mine on the south side of the dike has developed down dip more or less parallel to the strike of the dike. The main slope of the Maitland No. 2 mine on the north side has developed down dip and... 

Figure 6. Generalized schematic to show relationships of sample areas in the Black Beauty and Maitland No. 2 mines to the dike (hand with checks)...

I) 40 mL of the silver nitrate solution is treated with the same amount of sodium hydroxide solution in an Erlenmeyer flask ammonia is added until the precipitate of (AgOH)aq which is initially formed redissolves completely. Samples are now placed in 4 test tubes as follows 4 mL of formaldehyde solution (test tube 1), a mixture of 2 mL of benzaldehyde and 5 mL of ethanol (test tube 2), 3 mL of pure paraldehyde (test tube 3) and a mixture of 3 mL of freshly distilled acetaldehyde with 3 mL of water (test tube 4). 5 mL of the [Ag(NH3)2] solution are added to each test tube in the cold. The solutions in test tubes 1, 2 and 4 are colored black by the silver precipitate, while paraldehyde shows no reaction. A beautiful silver mirror is formed on the lower part of test tube 3 if it is warmed slightly. 

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