1770-1774

Manganese

• Torbern Bergman investigated pyrolusite,
• a mineral containing manganese dioxide, distinguishing it
• from known elements including lime and magnesia alba,
• but was unable to isolate the element.
• His friend Carl Wilhelm Scheele used pyrolusite,
• as an oxydizing agent to produce chlorine
• and knew it contained a new element,
• giving it the name maganese,
• but was also unable to isolate it.
• Johan Gottlieb Gahn, Bergman’s former assistant,
• was able to isolate the element from the mineral
• by reducing the dioxide with carbon
• to obtain this hard brittle silvery metal.

Atomic number 25

• Pyrolusite, also known as magnesia negra,
• was found, like magnesium ore,
• in Magnesia,
• and was used as a pigment in cave paintings
• and to remove color from glass.
• *
• Manganese ores are pyrolusite, braunite,
• psilomelane, and rhodochrosite.
• Manganese minerals include manganite, purpurite,
• and rhodonite,
• and manganese occurs in the iron ore
• spiegeleisen.
• *
• Manganese occurs naturally in some iron ores,
• particularly ores used to make Spartan steel
• in Greece,
• which made it stronger but not more brittle
• and led to widespread use in steels.
• *
• A small amount of manganese is alloyed with aluminum
• to make aluminum cans.
• A manganese compound replaces lead in gasoline
• to reduce engine knocking.
• *
• Manganese is a required trace mineral,
• a cofactor in many enzymes.
• Manganese dioxide is used as a cathode
• in batteries,
• and a manganese phosphate coating on steel
• prevents corrosion and rust.

Manganism

• Chronic overexposure to manganese results in physical
• and psychiatric disturbances, and maybe vocabulary confusion.
• Manganism is totally unrelated to the effects of Japanese comic books, manga,
• and has nothing to do with the mangonel, a kind of catapult,
• or magnetite, magnets, magnetism, or magnesium,
• just becauses their ores and lodestones were found in Magnesia.
• You are in no danger of contracting the syndrome by overeating mangos,
• or by swallowing too much milk of magnesia, or by being magnanimous,
• or having more than one manager, or seeing babies in mangers.
• The first three letters of manganism are not a prefix;
• the syndrome is unrelated to the male gender, specifically.
• Manganese is not a language spoken near Rio Manga in Honduras.
• But we are beginning to suspect that in many cases
• manganism is undiagnosed due to the rareness of the condition.