Southern black racer (scientific name: "Coluber constrictor"), the racer is more likely to suffocate or crush its victim into the ground, rather than coiling around it in typical constrictor fashion. Man remains the greatest enemy of black racers. Many are killed on highways and others are intentionally killed out of fear. The white chin causes some people to kill this snake, believing that it is a cottonmouth – a venomous snake more commonly called a water moccasin. The venomous snake has a white lining inside of its mouth. Racers are nonvenomous and do not breed with cottonmouths. Natural enemies include such birds of
Purified water in the reciprocal terms of electrical resistivity) and is due only to H and OH ions produced in the water dissociation equilibrium. This low conductivity is only achieved, however, in the presence of dissolved monatomic gases. Completely de-gassed ultrapure water has a conductivity of 1.2 × 10 S/m, whereas on equilibration to the atmosphere it is 7.5 × 10 S/m due to dissolved CO in it. The highest grades of ultrapure water should not be stored in glass or plastic containers because these container materials leach (release) contaminants at very low concentrations. Storage vessels made of silica are used for