256 



removed by cer- 

 tain additions* 



Albumen and 

 gelatine ufed in 

 fining wines, 



In fome in- 

 rtances an acid 

 is added* 



ON THE PROCESSES FOR CLARIFYING LIQUIDS. 



Albumen, gelatine, the acids, certain falts, lime, blood, 

 and alcohol, may in many cafes concur to operate the clarifi- • 

 cation of certain fluids, for which the common filters would be 

 infufficient. Nevertheless, thefe agents cannot be indiffe- 

 rently ufed, and the preference given to one rather than the 

 other always requires to be determined from a knowledge of 

 the fluid to be clarified. Accident has fhewn for example, 

 that two handfuls of marie reduced to coarfe powder, and 

 thrown into the fruit in the prefs, clarifies cyder and fmall 

 cyder. 



The effect of the albumen and gelatine is principally feen 

 in vinous liquors. For this reafon alio they are ufed in fining 

 wine, that is to fay, in producing that bright clearnefs which 

 they can feldom acquire, and preferve by fimple repofe. In 

 this cafe it is Sufficient, that one or the other of thefe two 

 fubflances fliould be.diffolvecl in a fmall quantity of water, 

 and the folution mixed with the cold wine. A fhort time af- 

 terwards a kind of net-work is feen to form itfelf through the 

 whole fluid, and foon afterwards this net- work contracting in 

 all directions, collects all the foreign fubflances, and carries 

 them to the bottom. 



In other inftapqes it is neceffary to heat the fluids with which 

 the albumen has been mixed, and in thefe cafes the clarifying 

 is effected at the inftant the mixture begins to boil, Mott 

 fyrups are clarified by this procefs, and hitherto no other pro- 

 cefs has been difcovered to produce a better effect. It has 

 alio been obferved that albumen alone is not always fufficient 

 to clarify liquids, even though they be heated fufficient to 

 caufe them to boil; but that it is neceffary to affift its action 

 by means of an acid, or fait with excefs of acid. In proof of 

 this we may offer the clarification of whey as an example. 



In fact, it is proved that whey, in which albumen has been 

 mixed, does not admit of the coagulation which carries the. 

 cheefy matter along with it, unlefs a portion of acidulous 

 tartarite of potafh or vinegar be added at the inftant the boil- 

 ing begins. 



It may alfo be conceived that the quantity of acid requifite 

 to be added in this cafe always bears relation to the ftate c»f 

 .the fluid, and that it would be abfurd to pretend to fix the 

 dofe in an invariable manner. 



• FrefU 



... 



