PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION 443 



of " isingrlass," or tjelatine, from hake sounds. This business was 

 established there nearly half a century ago, on a small scale, arwl 

 has been since continued. We have mentioned that Eockport is 

 nearly alone in this business, but perhaps we might say that it is 

 quite so, since there is a similar manufactory at Ipswich, estab- 

 lished and carried on by Rockport men, and so far as we know no 

 other in this section of country. When the business was first 

 established, some pretensions were made to a secret in the manu- 

 facture, but of late years it is generally known that there is no 

 ingredient entering into the composition of this isinglass except, 

 lug the sounds of the fish. 



The first efibrts at making this isinglass were very crude, the 

 whole work being done by hand power, the only machinery used 

 being plain wooden rollers. Of late years, however, new and 

 improved machinery has been introduced, and the works are 

 carried on by steam power. The process is very simple, the 

 sounds being thoroughly dried in the summer months, and when 

 they are ready for use are cut up and soaked, and made to pass 

 through sundry rollers, and exposed to a heating and drj ing pro- 

 cess. The isinglass, when complete, comes out in transparent 

 sheets or strips, rolled as thin as ribbon, and is ready for market. 



The business is quite extensively carried on, and draws on all 

 of the fishing towns of New Eng'land for the raw material, in the 

 shape of sounds. But little is done during the summer months, 

 but the manufactory is kept pretty busy during cold weather, and 

 its production finds a ready sale. It is used for a variety of pur- 

 poses, among others for the clarifying of liquors, sizing of cloth, 

 etc., etc. 



The preparation of isinglass was well understood by the ancients, 

 and is now carried on in difierent countries, being produced from 

 difierent species of fish in difierent lands. The best quality is 

 that manufactured in Russia, said to be obtained from the stur- 

 geon, a large fish of the Caspian sea and its rivers, and is a promi- 

 nent article of commerce. Isinglass of an inferior quality is also 

 manufactured in Brazil, from a variety of fish. In our own 

 country, we believe, there are similar establishments in the State 

 of New York, but with the exception of the two above named, 

 none that we know of in New England. 



Caviak. 

 The female sturgeon is much more valuable than the male. 



