VOi:. LXllI.j VHILOSOPHICAL TRANSACTIONS. 363 



isinglass, relying too much on the authority of some chemical authors, whose 

 veracity he had experienced in many other instances, he found himself constantly 

 disappointed. Glue, not isinglass, was the result of every process; and though 

 in the same view, a journey to Russia proved fruitless, yet a steady perseverance 

 in the research proved not only successful as to this object, but, in the pursuit 

 to discover a resinous matter plentifully procurable in the * British fisheries, 

 which has been found, by ample experience, to answer similar purposes. It is 

 now no longer a secret that our-|- lakes and rivers in North America are stocked 

 with immense quantities of fish, said to be the same species with those in Mus- 

 covy, and yielding the finest isinglass, the fisheries of which, under due en- 

 couragement, would doubtless supply all Europe with this valuable article. 



No artificial heat is necessary to the production of isinglass, neither is the 

 matter dissolved for this purpose; for as the continuity of its fibres would be de- 

 stroyed by solution, the mass would become brittle in drying, and snap short 

 asunder, which is always the case with glue, but never with isinglass. The latter 

 indeed may be resolved into glue with boiling water, but its fibrous recomposition 

 would be found impracticable afterwards, and a fibrous texture is one of the most 

 distinguishing characteristics of genuine isinglass. The reproduction of leather 

 might with equal reason be attempted from the former. 



A due consideration that an imperfect solution of isinglass, by the brewers 

 called fining, possessed a peculiar property of clarifying malt liquors, induced him 

 to attempt its analysis in cold subacid menstruums. One ounce and a half of 

 good isinglass, steeped a few days in one gallon of stale beer, was converted into 

 good fining, of a remarkable thick consistence : the same quantity of glue, under 

 similar treatment, yielded only a mucilaginous liquor, resembling diluted gum- 

 water, which, instead of clarifying beer, increased both its tenacity and turbid- 

 ness, and communicated other properties in no respect corresponding with those 

 of genuine fining. On mixing 3 spoonfuls with a gallon of malt liquor, in a tall 

 cylindrical glass, a vast number of curdly masses became presently formed, by 

 the reciprocal attraction of the particles of isinglass and the feculencies of the 

 beer, which, increasing in magnitude and specific gravity, arranged themselves 

 accordingly, and fell in a combined state to the bottom, through the well-known 

 laws of gravitation ; for, in this case, there is no elective attraction, as some 



* Upwards of 40 tons of British isinglass have been manufactured and consumed since this disco- 

 veiy was first made. — Orig. 



t As the lakes of North America lie nearly in the same latitude \^ ith tlie Caspian sea, particularly 

 Lake Superior, which is said to be of greater extent, it was conjectured they might abound witli the 

 same sorts of fish, and, in consequence of public advertisements distributed in various parts of North 

 America, offering premiums for the sounds of sturgeon, and other fisih, for tlie purpose of makinjj 

 isinglass, several specimens of fine isinglass, the produce of fish taken in these paits, have been lately 

 sent to England, with proper attestations as to the unlimited quantity which may be procured.— Orig. 



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