ACIPENSER HUSO. 



sounds of the common hake, Gadus merlucius, which is 

 thrown into water to macerate for a little while, and is then 

 taken out and pressed between two iron rollers, by which it 

 is elongated to the extent of half a yard or more. It is then 

 carefully dried, packed, and sent to market. 



An article called refined or transparent isinglass is made by 

 dissolving the New England isinglass in hot water and spread- 

 ing the solution to dry on oiled muslin. It is in very thin and 

 transparent plates, and is an excellent glue, but retains a 

 strong fishy odor. A preparation called Cooper's gelatine has 

 been introduced as a substitute for isinglass in making jellies. 

 It appears to be the dried froth of a solution of pure bone 

 glue. 



BRAZILIAN ISINGLASS is imported from Para and Maranham, 

 but it has not hitherto been ascertained from what fishes it is 

 procured, though it is obvious, from a superficial examination 

 of the commercial specimens, that they must have been ob- 

 tained from several species or genera. It comes to market 

 in the form of Pipe, Lump, and Honeycomb. 



Pipe Brazilian Isinglass must have been procured from a 

 large fish. It is prepared by drying the swimming-bladder 

 unopened. In some cases this bladder is imported distended 

 with air. The dried bladders or pipes are from ten to twelve 

 inches in length, and from two to two inches and a half broad. 

 Their weight is about five ounces. Their shape is somewhat 

 conical, tapering at one extremity, and broader at the other, 

 where on either side is a conical csecal prolongation. It is 

 devoid of smell, and is on that account less objectionable than 

 the lump variety. 



Lump Brazilian Isinglass consists of two swimming-blad- 

 ders placed side by side, considerably separated at one end 

 and communicating at the other extremity with each other. 

 When perfect, each lump somewhat resembles in shape a tor- 

 pedo. Its size varies. 



Honeycomb Brazilian Isinglass appears to be the largest 

 portion of the lump kind split open. The lump variety is 

 sometimes softened and rolled out into thin ribbons. On ac- 

 count of its deeper color and inferior solubility, Brazilian 

 isinglass is not in demand for domestic use, though as it is 

 sold in the cut state it is probably intermixed with the finer 

 kinds of Russian isinglass, and sold as such. As it is moder- 

 ately cheap and soluble, while it is free from any fishy smell, 



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