The Isinglass of Commerce. 251 



U't-sf Indian Isinglass. Under this name the isinglass 

 obtained in British and French Guiana enters into com- 

 merce. It is the produce of one or two siluroid fishes. In 

 British Guiana it appears to be obtained from the gilbackre 

 or gilbagre (Silurus Parkerii], a fish very abundant in the 

 estuaries of the rivers of the colony. A small quantity of 

 this fish-glue, as it is termed, is now exported from thence. 



In French Guiana some attention has also been given 

 to the preparation of isinglass obtained from the machorian 

 (Silitrus felis], which is especially employed in the clarifi- 

 cation of beer. Reduced into small shreds by the action 

 of a mechanical plane, it dissolves completely in cold 

 water, and is compared with Russian isinglass as two 

 to three. Its cheapness gives it also advantages over the 

 latter. 



North American Isinglass. Cod -sounds, which are 

 brought in great quantities from Newfoundland, are nothing 

 more than the salted air-bladders of these fishes. The 

 Iceland fishermen, as well as those of America, prepare 

 isinglass of a very excellent quality from cod-sounds, 

 though they are not acquainted with the method of clarify- 

 ing it which the Russians practise in preparing that article 

 from the sound of the sturgeon. 



Ribbon isinglass is obtained from the air-bladder of 

 the common hake (Merlucius vulgaris], or probably from 

 the fish passing under the name of hake on the coasts 

 of America (Phycis chuss). The air-bladder is thrown 

 into water to macerate for a little while, and taken out 

 and pressed between two iron rollers, by which it is elon- 

 gated to the extent of half a yard and more. It is then 

 carefully dried, packed, and sent to market. 



In the manufacture of ribbon isinglass from fish-sounds 

 it is customary to place the softened and moist or 



