228 



• N THE fROCESSES FOR CLARIFYING LIQUIDS. 



Clarifying 5s a 

 procefs of fomc 

 importance. 



Various me- 

 thods. 



Obje&of the 



procefs. 



Spontaneous 

 clarifying of 



fluid* 



XVI. 



Remarks 01 the Procejjes for clarifying Liquids. 

 Parmentier *. 



By Citizen 



A HE name of clarification is commonly given to a procefs 

 by means of which liquids are deprived of fuch foreign fub- 

 ftances as affect their tranfparency. 



( This operation, however fimple it may be in appearance, 

 deferves neverthelefs to be particularly attended to, efpecially 

 when we confider the advantages it affords in the chemical 

 and pharmaceutic arts. From thefe motives, I have thought 

 it might be ufeful to communicate fome general notions re- 

 fpecling the procefs. 



It is not my intention to develope in this place the different 

 methods made life of to obtain this purpofe, nor to fhew at 

 length the effects they produce with regard to each of the ob- 

 jects fubmitted to the operation. It will be fufficient limply 

 to point out the principal phenomena attending operations of 

 this kind. 



The purpofe to be anfwered, is, to clear the fluid from fuch 

 bodies as, without being diffolved, remain fufpended, and im- 

 pair its tranfparence and limpidity : but thefe bodies fometimes 

 are feparated by repofe or filtration ; in other inftances by the 

 action of the air, of heat, of light, of motion, and of fermen- 

 tation; and again in other inftances by means of agents, 

 which, by uniting the fcattered particles in the liquid intended 

 to be clarified, frequently change its nature, and no longer 

 allow them to remain in their former ftate.. We will begin 

 our examination by attending to fpontaneous clarification. 



This takes place only when the particles to be feparated are 

 decidedly of a lefs or greater fpecific gravity than that of the 

 fluid in which they are fufpended. In this cafe they may 

 unite at the bottom of the fluid, or at its furface, and form a 

 magma, which is very eafily removed if the feparation has 

 been complete. After this the fluid poffeffes all the tranfpa- 

 rence which can be defired, and the molt accurate filtration 

 will add nothing to its clearnefs. 



* Annalcs de Chimie. 



This 



