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Astringents

Collier's New Encyclopedia (1921)

substances which produce contraction and condensation of the muscular fiber: for instance, when MT. WILSON OBSERVATORY, MT. WILSON, CALIFORNIA. THE 100-FOOT DOME, VIEWED FROM THE 150-FOOT TOWER Enc. Vol. 1- p. 3 Mt. Wilson Observatory RC DESCRIBED BY SUM, DEC 2350 NOME, ALASKA EXPOSURES, 10 AM TO 2 P.M., AT HALF HOUR INTERYN International Film Service THE ARC DESCRIBED BY THE SUN ABOVE THE HORIZON AT NOME, ALASKA, ON THE SHORTEST DAY OF THE YEAR, DECEMBER 23, 1919. THE FIRST EXPOSURE WAS MADE AT SUNRISE, 10 A. M., AND THE LAST AT SUNSET, 2 P. M. THE OTHER EXPOSURES WERE MADE AT HALF-HOUR INTERVALS DURING THE DAY Mt. Wilson Observatory NORTH AND SOUTH SUN SPOTS, SEPTEMBER 9, 1908 Mt. Wilson Observatory NORTHERN PART OF THE MOON, AT LAST QUARTER. NIGHT IS ADVANCING FROM THE LEFT. THE DARK OVAL PLAIN, SURROUNDED BY A BRIGHT WALL, IS "PLATO." THE MOUNTAINS ABOVE AND TO THE LEFT OF "PLATO" ARE THE "LUNAR ALPS." THE LONGER RANGE, EXTENDING ACROSS THE UPPER LEFT-HAND PART OF THE VIEW, ARE THE "LUNAR APENNINES" Mt. Wilson Observatory THE BROKEN ROW OF YAWNING BLACK HOLES ALONG THE SOUTHERN PART OF THE MOON, AT LAST QUARTER. NIGHT ADVANCES FROM THE LEFT. TERMINATOR BETWEEN DAY AND NIGHT INCLUDE, TOGETHER WITH THE SECOND ROW TO THE RIGHT, WHOSE BOTTOMS ARE STILL IN THE SUNLIGHT, THE GRANDEST "RING PLAINS" AND "CRATER MOUNTAINS" ON THE MOON. THE LARGE SMOOTH ONE AT THE BOTTOM IS "PTOLEMAEUS" Mt. Wilson Observatory STAR CLUSTER M 22. SAGITTARII, AUGUST 6 Mt. Wilson Observatory IRREGULAR NEBULA M 17. SAGITTARII (OMEGA), JULY 29, 1919 Yerkes Observatory Mt. Wilson Cbservatory THE PLANET SATURN Underwood & Underwood TRANSMITTING CLOCKS FOR TIME SIGNALS, NAVAL OBSERVATORY, WASHINGTON, D. C. applied to a bleeding wound they so contract the tissues as to stop the hem- The contraction thus proorrhage. duced is different from that effected by an ordinary stimulant, and from that caused by the administration of a tonic.

What Has Changed in the Last Century

Collier's in 1921 defined astringents as substances that "produce contraction and condensation of the muscular fiber," stopping a bleeding wound by squeezing the tissue shut. Pharmacology now describes them quite differently: tannins, alum and metal salts act chemically, precipitating and cross-linking surface proteins to form a tough protective coagulum, and the tissue involved is not muscle at all. Their medical role has narrowed sharply — tannic acid dressings, widely used on burns in the 1920s and 1930s, were abandoned over liver toxicity, and serious bleeding is now controlled by pressure, sutures, electrocautery or agents such as aluminium chloride and ferric subsulfate. The word survives most visibly on cosmetic labels, on witch hazel and toner bottles, and in aluminium chloride solutions prescribed for excessive sweating. (The 1921 text here is interrupted by captions from astronomy plates bound into the same page.)

Written for this edition, 2026.