isinglass

plural isinglasses

1. uncountableusuallyA form of gelatin obtained from the air bladder of the sturgeon and certain other fish, used as an adhesive and as a clarifying agent for wine and beer.

   Isinglass flummery.—Put six ounces of isinglass into a quart of new milk, sweeten it, set it over the fire, and keep it stirring one way all the time, till it is jellied; pour it into basins, and when cold turn it out; you may put in orange flower water if you like.

   1830, Richard Dolby, The Cook's Dictionary, and House-keeper's Directory: A New Family Manual of Cookery and Confectionery, on a Plan of Ready Reference Never Hitherto Attempted, London: Henry Colburn and Richard Bentley, New Burlington Street, →OCLC, page 292, column 1

   5 more examples

   Isinglass is a substance well known in commerce, from its employment both in the arts and in domestic economy. It is the purest known form of animal jelly, and is obtained from the swimming bladder of a few kinds of fish, chiefly of the genus Sturgeon, the Acipenser of zoologists. This is indicated by some of its continental names, of which the English is no doubt a corruption;—thus, in German, Isinglass is called Hausenblase, from hausen the great sturgeon, and blase a bladder.

   1842, J[ohn] F[orbes] Royle, On the Production of Isinglass along the Coasts of India, with a Notice of its Fisheries (Goldsmiths'-Kress Library of Economic Literature; no. 32618), London: Wm. H. Allen and Co., Booksellers to the Honourable East-India Company, Leadenhall Street, →OCLC, page 1

   Isinglass is brought to market in different forms, sometimes in that of simple plates, at other times rolled up in different shapes, or cut into fine thread. When of good quality isinglass is of a whitish colour, thin, and semi-transparent, but tough and flexible, destitute of taste as well as of smell. The inferior kinds are thicker, yellowish-coloured, opaque, and sometimes have a fishy smell and taste. In boiling water isinglass is entirely dissolved, with the exception of a very minute portion of impurities.

   1858, Catalogue of the Collection of Animal Products Belonging to Her Majesty's Commissioners for the Exhibition of 1851, Exhibited in the South Kensington Museum, London: Printed for Her Majesty's Commissioners by W. Clowes and Sons, Stamford Street and Charing Cross, →OCLC, page 68, column 1

   Isinglass.—This is procured from the air-bag or swimming-bladder, sometimes termed the sound, of various fishes. […] Sometimes the bag is dried unopened, as in the case of the purse, pipe, and lump isinglasses of the shops. At other times it is laid open, and submitted to some preparation; being either dried unfolded, as in the leaf and honeycomb isinglasses; or folded, as in the staple (long and short) and book isinglasses; or rolled out, as in the ribbon isinglass.

   1868, Jonathan Pereira, “The Gelatinous Alimentary Principle”, in Charles A. Lee, editor, A Treatise on Food and Diet: With Observations on the Dietetical Regimen Suited for Disordered States of the Digestive Organs; and an Account of the Dietaries of Some of the Principal Metropolitan and Other Establishments for Paupers, Lunatics, Criminals, Children, the Sick, &c, New York, N.Y.: Samuel R. Wells, Publisher, 389 Broadway, →OCLC, page 103

   The sturgeon yielded a non-food product that was important for domestic and commercial use. This was isinglass, a gelatinous substance that was derived from the inner membrane of the air bladder (also called the swimbladder, or sound). Isinglass had a variety of uses. The Ojibway valued it as an effective binding agent in the manufacture of paint. Isinglass was also a product much in demand in Europe during the fur trade period. It was noted as producing a high quality glue and as a fining agent for beers and wines.

   1991, Tim E. Holzkamm, Victor P. Lytwyn, Leo G. Waisberg, “Rainy River Sturgeon: An Ojibway Resource in the Fur Trade Economy”, in Kerry [Margaret] Abel, Jean Friesen, editors, Aboriginal Resource Use in Canada: Historical and Legal Aspects (Manitoba Studies in Native History; 6), Winnipeg, Manitoba: University of Manitoba Press, →ISBN, page 128

   Not all fish have swim bladders, and those from certain tropical or semitropical areas (roughly 20° N and 15° S) provide the best quality isinglass for fining purposes. Of these fish, the threadfin family (Polynemoidia) provide excellent quality. In order to gain a desirable fining quality for a particular beer type, two or more kinds of isinglass may be blended. To illustrate this more precisely, Polynemus isinglass provides a fining that settles densely, whereas Silurus isinglass, from the great catfish family (Siluridae) in South America, gives a more flocculant fining but which settles less densely and consequently is more easily disturbed.

   1994, William A. Hardwick, editor, Handbook of Brewing (Food Science and Technology; 64), New York, N.Y.: Marcel Dekker, Inc., →ISBN, page 222

2. uncountableusuallyA thin, transparent sheet of mica (probably from its similarity to true isinglass and/or resulting from confusion with the term Muscovy glass for glazing made from mica, but also used for isinglass, which was chiefly produced in the Caspian Sea region of Russia, or Muscovy).

   TALC. / GENUS I. / ISINGLASS. / VITRUM. / Compoſed of broad, flat, cloſe, poliſhed Plates.

   1771, J[ohn] Hill, Fossils Arranged According to their Obvious Characters; with their History and Description; under the Articles of Form, Hardness, Weight, Surface, Colour, and Qualities; the Place of their Production, their Uses, and Distinctive English, and Classical Latin Names, London: Printed for R. Baldwin, in Pater-noster Row; and P[eter] Elmsley, in the Strand, →OCLC, page 10

   5 more examples

   There is a general error prevalent that mica is isinglass, and many times it is spoken of as isinglass, but there is a great difference between the two. Mica is mainly composed of silicate of aluminum, while isinglass is a fish gelatine or glue […]

   1914, A. J. Jarman, “Photographs upon Mica and Similar Material”, The Camera, London: [Camera Publishing Company], volume 18, number 7, OCLC 50541188, page 398

   MICA (ISINGLASS). Mica is valuable because of its perfect cleavage, transparency, elasticity, non-conductivity of heat and electricity, resistance to decomposition, and non-inflammability. It is mostly used as an insulating material in the manufacture of electrical apparatus.

   1918, “Economic Relations and Military Uses of Materials”, in Herbert E[rnest] Gregory, editor, Military Geology and Topography: A Presentation of Certain Phases of Geology, Geography and Topography for Military Purposes, New Haven, Ct.: Yale University Press, →OCLC, page 266

   The dashboard's genuine leather, / With isinglass curtains y' can roll right down, / In case there's a change in the weather.

   1943, Oscar Hammerstein II (lyrics), Richard Rodgers (music), “The Surrey with the Fringe on Top”, from Oklahoma!

   THE FRONT DOORS OF MY STOVE HAD WINDOWS of isinglass (mica) which needed replacement. While impervious to heat, isinglass is quite fragile and one must avoid touching these panels when using the doors. The panels are held in place by a frame bracket screwed to the inside of each door. Fortunately, a supply of extra mica panels was found in the house.

   1976 September, Don Yule, “Cooking and Eating the 19th Century Way”, in The Old-House Journal, volume IV, number 9, [Brooklyn, N.Y.]: Old-House Journal Corp., →OCLC, pages 2–3

   Do you enjoy the amber glow seen through the isinglass window of a wood stove? […] Muscovite (colorless, white, or pale red or green) mica is also common[…]; it was named for Moskva (Moscow), where much of Europe's mica was mined. Isinglass, mentioned above, consists of thin, transparent sheets of muscovite.

   2009, James S. Monroe, Reed Wicander, The Changing Earth: Exploring Geology and Evolution, 5th edition, Belmont, Calif.: Brooks/Cole, →ISBN, page 76