1140 FISHERIES OF THE UNITED STATES. [HO] 



Uses of fish-olue — Continued. 



years the high cost of the raw material and the great amount 

 of labor involved in its manufacture have precluded its general 

 adoption for mechanical purposes. It was known to the an- 

 cients by the name of ichthyocolla, or fish glue, and is often al- 

 luded to by Dioscorides and Pliny. In different parts of the 

 world it is obtained from the swimming bladders, or sounds, of 

 different kinds of fish, and the isinglass of commerce is conse- 

 quently of various qualities. The best is found among the va- 

 rieties imported from Eussia, particularly that which is brought 

 to St. Petersburg from Astrakan, and said to be obtained from 

 the sturgeon, called the beluga, of the Caspian Sea and the 

 rivers flowing into it. These sounds, after being cleaned and 

 dried, are called Eussia isinglass, and were until within a few 

 years largely used in the manufacture of cement for leather 

 belting, also in other industries where adhesives of the great- 

 est possible strength and flexibility are required. They are dis- 

 solved in water by boiling, and are generally used mixed with 

 other glues. 



" In America the sounds of hake and other fish, after being soft- 

 ened in water, are rolled by powerful machinery into very thin 

 ribbons and dried, forming what is known as ribbon isinglass. 

 This is used principally for the fining of beer. 



"The Turks use a fish-glue for fastening precious stones in their 

 settings, and the Laplanders join together the pieces of wood 

 of which their bows are made with glue extracted from the 

 skins of perch. This glue, which was made only in small quan- 

 tities, owed a considerable portion of its wonderful tenacity to 

 the fact that the first time it dried was upon the article cemented. 

 But, though it has long been known that glue is much stronger 

 when freshly made than after it has been dried and redis- 

 solved, it has been the custom, from time immemorial, to dry 

 all glue into hard sheets or cakes, in order that it might thus 

 be preserved from putrification until wanted for use. This is 

 a tedious and expensive operation, involving great risk to both 

 the manufacturer and consumer, as sudden changes in the 

 weather while the glue is drying will often cause the total loss 

 of a whole batch ; or, what is worse for the consumer, may so 

 taint the glue that, though saved to the manufacturer by sub- 

 sequent drying, the injury which it has sustained will appear 

 whenever it is dissolved for use. The evils of this method of 

 making glue are so great that many attempts have been made 

 to overcome them, and thousands of dollars have been ex- 

 pended by many large manufacturers in unsuccessful efforts to 

 find some means' of preserving glue in a liquid form without 

 injury to its adhesive qualities. It was found, however, that 



