On ihe Edulcoration -of Fl/h^ Oil^ 105 



ton produced which had been printed therewith inflead of 

 gum-fcnegal, and froni experiments made in Manchefter, it 

 appears that the hyacinthus 71071 J'crlpius iiiaVj in many cales, 

 be found a ufetul i'libftitutg for gum-arabic. 



XX. On thi Edulcoration of pi fh- Oil, By Roberx ■ 

 DossiE, Ejq* 



Explanation of ihe Principles on which the Purification cf 

 Fiftj-Oil may he perfor-jud, and of the Ufes to ivhich it is- 

 applicable. 



X HAT the foetid fmell of fifh-oil is chiefly owing to pu- 

 trefacllon, it is nnneceflary to ihow j but, though this be the 

 principal caijfe, there is another likevvife, which is, ullion, or 

 burning the oil, occafioned by the ftrong beat employed for 

 the extracting it from the blubber of the larger fifti, and 

 which produces a ftrong ernpvreumatic Icent that is not al- 

 ways to be equally removed bv the fame means as the putrid 

 fmell, but remains fomelimes very prevalent after that is 

 taken away. 



In order to the perfeft edulcoration of oils there are con- 

 fequently two kinds of fcetor or ftink to be removed ; viz. the 

 putrid, and the empyreumatic \ and the fame means do not 

 always equally avail againft both. 



The putrid fmell of fi(h-oil is of two kinds : the rancid, 

 which is peculiar to oils; and the common putrid fmell, 

 which is the freneral t^c^ of the putrefiftion of animal 

 fluids, or of the vafcular folid?.^ when commixed with aque- 

 ous fluids. 



Fifli-oil has not only rancidity, or the firft kind of putrlj 

 fmells peculiar to oils, but alfo the fecond or general kinds; 

 as the oil, for the mod part, is commixed with the gtlntinous 

 humour common to all animals, and fonie kinds with a pro- 

 portion of the bile likewife; and thofe humours putrefying 

 combine their putrid fccnt with the rancidity of the oil, and, 

 in cafes where great heat has been ufed, with that and the 

 enipyreunia alfo. 



Tlie reafon of the prefence of the gelatinous fluid in fifli- 

 pil is this: that the blubber, which confilU partlv of adipofe 

 »eficles, and partly of the mernbrana cellulofa^ which con- 



* From the Trniifiuliotis fjf the Socitiv for the Encim-ayenunt of At1s, isir, 

 vol. XX. So far b.ick as the year lyCi tlicfociciy votixi him a bounty of 

 .'.nc hui\drcd pounds for thii co;nmuiin.ati''<i, thou^li they did noi jnibhlh 

 it tiJi loo^. 



tains 



