On the EduJcoratkn of F'iJJ:-Oil. 113 



pnOCESS THE THIRD. 



To purify F'lfi-O'il with the AJfijlance of Heat, where jhe 



greaitjl Purity is required, and particularly for the IVool- 



len Mariufa&ure. 



Take a gallon of crude (linking oil, and mix with it a 

 fiuarter of an ounce of powdered chalk, a quarter of an ounce 

 of lime flaked in the air, liud half a pint of water; ftir tliein 

 together, and, when they have ftood fome hours, add a pint 

 of water and two ounces'of pearl -allies, and place them over 

 a fire that will juft keep them limmering, till the oil appears 

 of a light amber colour, and has loll all fmell, except a hot, 

 greafy, foap-like fcent. Then fupcradd half a pint of water 

 in which an ounce of (iill has been dilTolved ; and having 

 boiled them half an hour, pour them into a proper vcilcl, 

 and let them ftand till the feparation of the oil, water, and 

 lime be made, as in the preceding procefs. Where this ope- 

 ration is performed to prepare oil for the woollen manuhic- 

 ture, the fait may be omitted ; but the feparation of the lime 

 from the oil will be flower, and a longer boiling will be ne- 

 cefTary. 



If the oil be required yet more pure, treat it, after it is fe- 

 parated from the water, '&c. according to the fecond procefs, 

 with an ounce of chalk, a quarter of an ounce of pearl-afhes, 

 and half an ounce of fait. 



Ohfervations on Procefs the Firfl, 

 This procefs may be performed on any kind of fifli or feal- 

 oil that is putrid and Itinking, and will improve it in fmell, 

 and generally render the colour lighter, if previoufly dark and 

 brown: it will alfo conduce to render thefe oils filter for 

 burnine:, which are, in their crude (late, faulty in that point; 

 but it will not meliorate them to the full degree they admit 

 of even without heat, and ihould therefore be praftife'd when 

 only a moderate improvement is required. 



Secondly, When the oil is taken oft' from, the dregs and 

 brine, the dregs which fwim on the brine fliould be taken off 

 it alfo, and put into another veiVel of a deep form ; and on 

 fiandinff, particularly if frefli water be added and ftirred with 

 them, nearly the wliolc remaining part of the oil will fepa- 

 rate from the foulnefs ; or, to fave this trouble, the dregs, 

 when taken off, may be put to any future quantity of oil 

 that is to be edulcorated by this method, which will anfwer 

 the fame purpofe. 



Vol. XV. No. 58. I Ohfervations 



