10 FISH ISINGLASS AND GLUE. 



The use of isinglass for edible purposes has become practically 

 obsolete since the manufacture of gelatin on a large scale has become 

 a function of the slaughter and packing houses. It was formerly- 

 utilized to stiffen jellies and jams and in the manufacture of con- 

 fectionery, but has no peculiar medicinal properties. Some fish 

 sounds have been esteemed as an article of food ; thus it is said that 

 fried cod sounds have a flavor resembling that of oysters similarly 

 cooked. 



Isinglass has long been used as a clarifying agent for beverages 

 fcuch as cider, wines, and malt liquors. The peculiar clarifying 

 action is purely mechanical, those substances causing turbidity be- 

 coming entangled in the slowly sinking network of gelatinous mate- 

 rial. This property is not possessed to the same degree by gelatin 

 prepared from animal bones, hoofs, or hides, and such gelatin is far 

 less efficient as a clarifier. English brewers of malt liquors prefer 

 the Penang product, while Scottish brewers employ Russian leaf 

 isinglass. English cider manufacturers generally use Russian long 

 staple. American brewers formerly considered Russian isinglass as 

 superior to other kinds, but later adopted the use of the ribbon 

 isinglass made from hake sounds in this country. 



White wines are usually clarified by isinglass. The isinglass is 

 allowed to swell in water and then in wine until it is practically 

 transparent. It is thoroughly beaten with more Avine, a little tartaric 

 acid being eventually added ; after filtering through linen it is stirred 

 into the wine. One ounce of isinglass will usually clarify 200 to 500 

 gallons of wine in 8 to 10 days. 



In the storage of beer after the primary fermentation all sus- 

 pended particles do not settle in the stock tanks. This is true of 

 starch granules, bacteria, some of the protein matter, etc. From 

 storage the beer is run into chip casks where it is carbonated by 

 charging with carbon dioxide directly or by the addition of young 

 beer, and at the same time clarified or fined. This latter process is 

 carried out by the addition of chips or of isinglass, or by filtration. 

 When isinglass is employed, it is treated with sour beer, acetic, or 

 other weak acid whereby it is not actually dissolved, but is "cut" 

 by the acid. Finings thus prepared have an excellent clarifying 

 action. One pound of isinglass will fine 100 to 500 barrels of beer. 



Isinglass is the basis of some of the best adhesives. Although 

 formerly used for postage stamps, envelopes, and gummed paper, the 

 dextrins prepared from starch have largely taken its place. Mixed 

 with two parts of alcohol a " diamond " cement is obtained, the 

 cooled solution forming a white, opaque, hard solid. Dissolved in 

 acetic acid another powerful cement is obtained, especially useful in 

 repairing glass, pottery, and similar articles. Various modifications 



