[ill] FISHERIES OF THE UNITED STATES. 1141 



Uses of fish-glue — Continued. 



though glue could be preserved from decomposition, the acids 

 employed for that purpose not only injured tbe material upon 

 which the glue was used, but caused slow chemical changes in 

 the glue itself, greatly impairing, and after a time completely 

 destroying, its adhesiveness. The attempt was, therefore, aban- 

 doned, and, except in the preparation of glue for use in small 

 quantities, where convenience was of more importance than 

 strength or durability, the old metbod continued to be univer- 

 sally employed. This was the state of the art when the inventor 

 of liquid fish glue began his experiments. His attention was 

 first called to the practical difficulties to be encountered in the 

 working of glue while engaged in the business of manufacturing 

 furniture. Becoming convinced that there ought to be some 

 way to avoid these difficulties, he commenced a long series of 

 careful experiments, which, carried on through many dis- 

 couragements and repeated failures, finally resulted in the 

 discovery of a new method of manufacturing glue, by which it 

 may be preserved in liquid form so as to retain its original 

 strength for years in any climate. 



" Careful experiment showed what kind of raw material possessed 

 the qualities of strength and flexibility in the highest degree, 

 and resulted in the production of the Russia Belting Cement, 

 so called because it has proved to be superior to, and is largely 

 used in place of, Russia isinglass. This cement, which is a 

 liquid isinglass of great purity, specially prepared for use upon 

 leather, is used by nearly all the large manufacturers of leather- 

 belting in the United States, and is now being introduced in 

 foreign countries. 



u The isinglass, after being separated from the raw material by steam 

 extractors, which allow the shortest possible exposure to heat, 

 is passed through a refining process, by which any impurities 

 contained in the liquid are removed. It is then brought down 

 to the proper density by evaporators, designed expressly for 

 this purpose, which perform their work without heating the 

 liquid any hotter than can be comfortably borne by the naked 

 hand. After being evaporated to the proper consistency the 

 liquid isinglass is subjected to chemical treatment and run 

 into cooling tanks, from which it is drawn into barrels ready 

 for shipment. 



"The business of preparing dried codfish for the market by strip- 

 ping off the skins and bones and packing the fish in small 

 boxes, which was commenced in the year 1872, had at this time 

 grown to such magnitude that nearly 3,000 tons of skins and 

 bones were produced annually in the city of Gloucester alone. 

 A very small portion of this material was used in the manufact- 



