16(5 On the l^dulctrdtion 6f Fiji- Oil. 



fains the gelatiilAus fluid, is, for the mod: part, kept a con- 

 siderable time before the oil is feparated from it, either from 

 the want of convenient opportunities to extraft the oil, or in 

 order to the obtaining a larger proportion ; as the putrid ef- 

 fervefceuce which then comes on, rupturing the veficles, 

 makes the blubber yield a greater quantity of oil than could 

 be extracled before fuch change was produced ; and the ve- 

 ficles of the tela cellulofa, containing the gelatinous matter, 

 being alfo burlt from the fame caufe, fuch matter being then 

 rendered faponaceous by the putrcfa£lion, a part of it mixes 

 intimately witli the oil, and conftitutes it a compound of the 

 proper oleaginous parts and this heterogeneous fluid. 



The prefence of the bile in fiflj-oil is occafioncd by its 

 beinor, hi many cafes, extra6led from the liver of the fifli ; 

 which is not to be fo profitably done by other means as by 

 putrefaftion ; and the bile being confequently difcharged, to- 

 gether with the oil from the vefl'els of the liver containing 

 them, combines with it, both from the original faponaceous 

 property of bile, and from that which it acquires by pulre- 

 ra(3;ion. 



This holds good particularlv of the cod-oil, or common 

 train, brought from Newfoundland, which, from its high 

 yellow colour, vifcid confiftence, and repugnance to burning 

 well in lamps, manifefts fenfibly the prefence of bile and the 

 gelatinous fluid ; which latter, by the faponaceous power of 

 the bile, is commixed in a greater proportion in this than in 

 any other kind of fifli-oil, 



A tendency to putrefy, or at moft but in an extremely flow 

 manner, is not an abfolute property of perfect oils in a fimple 

 or pure ftate, but it is a relative property dependent upon 

 their accidental contact or commixture wilfi the aqueous 

 fluid. This is evident from the cafe of oils concreted into a 

 febaceous form ; which being perfeAly oleaginous and un- 

 combined with any water, except fuch as enters into their 

 component parts, will not putrefy unlefs water, or iomelhing 

 Containing it, is brought in contart with them. But the fluid 

 animal and moft vegetable oils being compounded of perfedt 

 oils with other mixed fubftanccs, either fub-oleaginous or ge- 

 latinous, have always a putrefcencc per Je, or tetidencv to 

 putrefy, without further admixture of aqueous moilture. This 

 commixture of heterogeneous mailer in fifh-oil, particularly 

 of the gelatinous Puid and bile, gives rife to a further princi- 

 ple of purification than fimple cilulcorntion, or the removing 

 the fcetor ; for the prefence of fuch humours in the oil ren- 

 ders it fubjeft to a fecond putrefcence fer fe, fuppofing the 

 firft corredted; makes it unfit fur the purpofe of the woollen 



niunufa»5ture, 



