238 The Commercial Products of the Sea. 



CHAPTER VIII. 



THE ISINGLASS OF COMMERCE. 



Description and uses of isinglass Fish from which obtained Russian isinglass 

 Vesiga Brazilian isinglass West Indian isinglass North American 

 isinglass Chinese isinglass Fish maws and sharks' fins. 



ISINGLASS, one of the purest and finest of the animal glues, 

 is a product the preparation of which was long carried on 

 almost exclusively in Russia, and chiefly obtained from the 

 sturgeon. The value of the isinglass from this fish is 

 chiefly due to its peculiar organic texture, on which the 

 property of clarifying wines and beers depends. No arti- 

 ficial isinglass, however pure the gelatine, or identical as to 

 chemical composition with the air-bladder of the sturgeon, 

 answers the purpose of the preparers of fermented liquors. 



Isinglass is brought to market in different forms ; some- 

 times in that of plates or lumps, or in the form of a bag or 

 purse, at other times rolled up in different shapes, which 

 pass under the names of book, leaf, long and short staples, 

 tongue or pipe, and it is cut into fine threads. When of 

 good quality, isinglass is of a whitish colour, thin, and semi- 

 transparent, but tough and flexible, destitute of taste as 

 well as of smell. The inferior kinds are thicker, yellowish 

 coloured, opaque, and sometimes have a fishy smell and 

 taste. When placed in cold water, it becomes soft, then 



