Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 4, 1802).djvu/131

111&#93; SPE Ish, somewhat un6tnoui; substance, and t nearly fisstitute of smell ; bal- ing obtnincd from the head of the Fkysettr macro-cepkalas, L. a spe- cies of whale. As the manner of preparing this expensive article is studiously con- cealed, we shall only observe, that gotji sp-ermiiceti is perfeftly white, glossy, and semi-transparent; ra- ther soft and oily to. the toueh, though friable arid dry; its taste i-fesembles that of fresh butter, and it's sttlell is faint, like that of tal- low. It is said to be often adul- terated with <vax ; but such fraud miy be speedily dctefted, by the pecfuliar smell of the latter sttb- stance, and by the dullness of the colour. A "preparation of the oil obtained from the tail of the whale, is likewise vendedfor genuine sper- maceti; but, as it assumes ti yel- low shade on exposure to the air, such imposition may be easily dis- covered. It win, however, be ne- cessary, in all cases, to preserve spermaceti in vessels, closely se- clnded from the atmosphere ; as this drug is apt to become rancid, and to acquire a disagreeable co». lour ; though it may be restored to its original purity, by steeping it in a ley, composed of quick-lime and alkaline salts. Coarse or raw spermaceti, pays, on importation, in British ships, the sum of 19s. 5|d. per cwt. ; and, if refined, it is subjett to the sum of 8|d. per lb. The quan- tity imported, however, being not only inadequate to the demand, but also grossly adulterated, Mr. Smith Gibbes (now Dr. Gibbes of Bath) proposed, in the 2nd Part of the Philosophical Trans- aSiions of the Royal Society, for 1/04, to convert animal muscles into a fatty substance, resembling STE C,.t spemiaceti : His chemical process consists in enclosing the carcass of a horse, cow, 8cc. in a box perfo- rated with holes, and immeising it in a clear stream or river, for the space of a month, or longer; when ,it will be converted into a mass of unftuous matter. A certain por- tion of nitrous acid (aqua fortis) is next poured on this cheest/ sub- stance, in order to discharge the offensive smell, and separate the fat in a pure, thoughsomewhat yellow- ish, state. Such colom- may, how- ever, be removed, and the whole tolerably bleaclied, by submitting it to the action of the oxygenated muriatic acid. Dr. Gibers fiu- ther observes, that this remarkable conversion may be effeded in the course of three days, by pouring nitrous acid on apiece of lean meat. Nay, the iHustrious I-ord Bacoj^ nr:'ntions the following curious circumstance in his work, entitled " Sylva Sylvarnm ;" namely, that the flesh of animals may be changed into a fatty substance, by cutting it in pieces, which are to be put ia a glass covered with parchment, and thus allowed te stand six or seven hours in boiling water. " It may be an experiment of profit (says Bacon) for making grease or fat, for many purposes ; but then it must be made of such flesh as is 7iot edible, as horses, dogs, bears, foxes, badgers, Jcc." It appears, likewise, from Dr. Gibbes's Me- moir, that the-putrefadtive process i^ not necessary for eticfting this change ; as it would waste a con- siderable portion of flesh, that might serve to form a larger mas« of waxy substance. Great quantities of sperniacet are annually consumed in the ma- nufadture of candles and tapers, which are preferable to tliosetnade of