BY-PRODUCTS OF FISHERY INDUSTRIES 225 



used in the manufacture of this glue in the United 

 States. 



Fish glue is the only common liquid glue. The so- 

 called animal glues (hide and bone glues) will not 

 dissolve in cold water and, when dissolved in hot 

 water, form jellies when cooled. For this reason fish 

 glue is adapted for uses to which other glues are 

 unsuited. It is a strong adhesive, yet it is sufficiently 

 flexible to be used in the preparation of flexible glues. 

 It is used wherever a strong, ready-prepared adhesive 



is required. 



Isinglass 



Many persons confuse isinglass with mica. True 

 isinglass is prepared from the sounds or swimming- 

 bladders of the sturgeon, hake, and other fishes. It 

 is often said that the large meat-packing houses 

 utilize everything except the squeal of the pig; on 

 the other hand, the fish packers utilize even the 

 sounds of the fish. There is some truth in this pun, 

 for in the large fishery centers, such as Gloucester 

 and Eastport, the fish packers do not waste any 

 part of the fish. But the fishing industry is so widely 

 scattered along thousands of miles of coast-line that 

 the waste of many fishery products in out-of-the-way 

 places is unavoidable. 



The best isinglass is made in Russia from the 

 sounds of the sturgeon. The manufacturing opera- 

 tions are simple, the sounds being split open, care- 

 fully washed, cleaned, and dried. The prepared 

 sounds are treated in various ways, depending upon 

 the form desired. Long staple, short staple, leaf, 

 book, and cake isinglass are the chief forms in which 



