Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 3, 1802).djvu/305

283&#93; OIL jated with the ingredients in a si- milar manner, and die agitation occasionally renewed for one or two days. The v/hole is then suf- fered to stand at rest, when the water and chalk will be precipi- tated, and the oil will be consider- ably puritied, though not so com- pletely as by the following pro- <;ess: 2. Let an ounce of ]iulverized chalk be added to a gallon of crude, fetid oil, or to a similar quantity of the fluid prepared as above direct- ed, and the whole be repeatedly stirred, as before described. After it has been mixed for ses'eral hoars, one outice of pearl-a^hes, dissolved in four ounces of water, is to be added, and the stin-ing continued, at intei"vals, for some hours ; when 3 solution of two ounces of salt, in one pint of water, must be add- •ed, and die agitation occasionally re- peated during the next two days. — Now, the mixture ouglit to stand for several days, when the brine will separate from the oil, which will be greatly improved both in smell and colour. Should a greater degree of purity be required, the proportion of pearl-ashes ought to be increased 5 and the [x^riod in- tervening between the addition of the salt and water prolonged : last- ly, if the same operation be re- peated, and the quantity of ingre- dients be reduced one- half each time, tlie oil may be brought to a very light colour, and its smell rendered equally sweet as the com- mon spermaceti.. — By this treat' ment, the coarsest cod, or seal- oil, may be made to burn ; and, though it be too putrid for use, it may be so far corrected by the first process, as to be in all respe6ts equal to that commonly sold. In the year 179S, a patent was OIL Uh granted to Mr. Collier, for' a chemical process for freeing fish- oils from their impurities, in point of smell, taste, and colour ; and also for improved strainers for oils and other liquids, &:c. The whole is performed in the following man- ner : first, the patentee pours an/ quantity offiih-oil, or a mixture of different kinds of oil, into a vessel, M'hich is healed to the temperature ofllOorl'iOdegreesofFaluenheit's thermometer J v.hen a portion of caustic mineral alkaU is added, t!ie weight of which is equal to four parts to the hundred of the oil. The mixture is next agitated; an.!, after the .sediment and salt have subsided, it is drawn ott into ano- ther vessel, containing a sufficient quantity of finely pulverized, fresh- burnt charcoal, and a small propor- tion of diluted sulphuric acid.' The agitation is repealed; and, when the coal, together with the salhie and aqueous particles, have subsid- ed, the oil is passed through certain strainers, and thus rendered per- fecll}'- transparent and ht for use. — Such is the patentee's process ; but, as a description of the vessels employed in edulcorating the oil, would be unintelligible, without tiie aid of an engravuig, the reader will couault the lOtli volume of the Ecpertory of Arts, &:c. ; where the' patent is fully described, and illus- trated with a plate. Beside its utility for lamps, ani- mal oil possesses a valuable pro- perty which deserves attention. If one drop be laid on a bug, fly, wasp, or earw ig, it will cause the immediate death of those trou* blesome vermin ; and, even Avhen it is damaged, it may, according to Mr. BucKNALL, be advan- tageously applied to fruit-trees, jibout a month after they have been washed