PURIFICATION OF FISH-OIL. \\ 



The ochrous earth of iron, commonly called red ochre, Jias Red ochre may- 

 an abforbing power on the putrid parts of oil, but combines turc> 

 fo ftrongly, that the feparation is tedious even with the addi- 

 tion of brine ; if, neverthelefs, it is added when chalk and 

 lime have been fome time commixed with the oil, as in pro- 

 cefs the firft, it will promote the edulcorative intention, and 

 will fubfide along with them ; and, as it has fome advantage 

 without increafing the expence, unlefs in the mod incon- 

 fiderable degree, its ufe may be expediently admitted in that 

 procefs. 



EfTentiat and ethereal oils are applicable to the prevention Volatile oils in. 

 of putrefaction in the mixed and folid parts of vegetables, softly"* *" 

 but are not fo to the edulcoration of fetid oils ; and if they had 

 the delired effect, they would not, on account of their price, 

 anfwer the commercial end, unlefs the due effect was pro- 

 duced by adding them to the oils in a very fmall quantity. 



The fame holds good of fpirits of wine as of eflential and So likewife are 

 ethereal oils, both with refpea to their efficacy and the e x- alcoholandether * 

 pence. 



Water has an edulcorative action on fetid oils, by carrying Water by agita- 

 off the moil putrid parts of the gelatinous fluid or bile, in **"» improves 

 which, as was above explained, the principal fcetor refides, f 00 n p Utre fy 

 if the quantity added be large, and an intimate commixture a S a in» 

 be made of them by ftirring them together for a confider- 

 able time : this only partially removing thofe heterogeneous 

 putrefcent fubftances, the remaining part foon acquires the 

 fame ftate and the oil again grows fetid, though not to the 

 Tame degree as before. 



Water is, however, a neceffary medium for the action of It is necefiary 

 falts and the feparation of alkaline earths and calces of metals, ^ c h e e fl ^ m P oun * 

 when they are employed for the edulcoration of oils, as will 

 appear from a confi deration of my proceues. 



Air edulcorates oil by carrying off the mofl putrid parts, Air is ftill lefs 

 which are neceffarily extremely volatile. It may be made to efte<aual * 

 act on them either by fimple expofure of them to it with a 

 Jarge extent of furface, or by forcing it through them by means 

 of ventilators as has been practifed by fome dealers ; but is 

 now, I believe, neglected on account of their finding the im- 

 provement of oils by it not adequate to the trouble, as the 

 gelatinous matter and bile, not reduced to a certain degree of 

 putrefaction, being left behind, putrefy again to nearly the 

 fame degree as before. 



It 



