Word of the day: styptic

The word of the day is styptic:

1. serving to contract organic tissue; astringent; binding.
2. serving to check hemorrhage or bleeding, as a drug; hemostatic.

c.1400, from O.Fr. stiptique, from L. stypticus "astringent," from Gk. styptikos, from styphein "to constrict, draw together." Spelling influenced by L. and Gk. words.

(http://dictionary.reference.com/browse/styptic)

"The main medicinal use of alum was, as it still is today, as an astringent to improve wound healing. The modern styptic used to close up razor nicks occurring after wet shaving is alum-based."

 - David Rickard, "The Many Faces of Fool's Gold", May-June 2016 American Scientist (http://www.americanscientist.org/issues/feature/2016/3/the-many-faces-of-fools-gold/1)

Word of the day: alum

The word of the day is alum:

1. Also called potash alum, potassium alum. a crystalline solid, aluminum potassium sulfate, K ₂ SO ₄ ⋅Al ₂ (SO ₄ )₃ ⋅24H ₂ O, used in medicine as an astringent and styptic, in dyeing and tanning, and in many technical processes.
2. one of a class of double sulfates analogous to the potassium alum, as aluminum ammonium sulfate, having the general formula R ₂ SO ₄ ⋅X ₂ (SO ₄) ₃ ⋅24H ₂ O, where R is a univalent alkali metal or ammonium, and X one of a number of trivalent metals.
3. (not in technical use) aluminum sulfate.

early 14c., "whitish mineral salt used as an astringent, dye, etc.," from O.Fr. alum, from L. alumen "alum," lit. "bitter salt," cognate with Gk. aludoimos "bitter" and Eng. ale.

(http://dictionary.reference.com/browse/alum)

"The production of one mordant, pure alum, from pyrite has been described as the point of origin of the modern chemical industry, because the process required not only the manufacture of a chemical substance but also its purification."

 - David Rickard, "The Many Faces of Fool's Gold", May-June 2016 American Scientist (http://www.americanscientist.org/issues/feature/2016/3/the-many-faces-of-fools-gold/1)

Word of the day: mordant

The word of the day is mordant:

4. a substance used in dyeing to fix the coloring matter, especially a metallic compound, as an oxide or hydroxide, that combines with the organic dye and forms an insoluble colored compound or lake in the fiber.

late 15c., "caustic" (of words, speech), from M.Fr. mordant, lit. "biting," prp. of mordre "to bite," from L. mordere "to bite or sting" (see smart (v.)). Related: Mordantly. The noun sense in dyeing is first recorded 1791; the adj. in this sense is from 1902.

(http://dictionary.reference.com/browse/mordant)

"Sulfuric acid is a relatively recent manufactured chemical.  Prior to this, the important analogous chemical substances were the sulfate salts of iron, copper, and aluminum, known to the ancients as the vitriols...  They were used as mordants in the dyeing industry. In order for natural dyes to be fixed in the cloth—and not be washed out during the next rainy day—it is necessary to treat the cloth with a mordant. The mordants widely used in dyeing were solutions of the vitriols."

 - David Rickard, "The Many Faces of Fool's Gold", May-June 2016 American Scientist (http://www.americanscientist.org/issues/feature/2016/3/the-many-faces-of-fools-gold/1)