CIM
CIT
( 289 )
on the furface of which it fwims like cream,readily coagulating like blood by Ample reftand extravalation, and appears to be compofedof water, of an oily fubftance confifting ofglobules, of a heavier matter like cheefe whichremains at the bottom after coagulation, and offome earth. Chyle readily turns four by keep-ing, but gives no fign of acidity when frelh.The nature of the aliment makes fome, thougha very fmall change in the feniible qualities ofchyle. Thus it is fometimes tinged when co-louring matter has been taken into the ftomach.
It does not however fliew any marks of con-taining iron, even when the animal has been inthe habit of taking this metal.
CIMOLITE a of Klaproth . Cimolia ofPliny .
The colour of this mineral is a light greyifh-white, inclining to pearl-grey; but by expofureto the air it acquires a reddifh tint. It occursin mafs, forming large ftrata; its fraCture isearthy, uneven, and its texture more or lefsflaty. It is opake, of a greafy Iuftre, and maybe fcraped with a knife like fteatite. It adheresfirmly to the tongue, ftains the fingers in fomedegree, and, though foft, is very tough, anddifficultly pulverizable. Sp. gr.—2.0.
When expofed to the aCtion of the blow-pipeper fe, it becomes at firft of a dark grey colour,but afterwards recovers its whitenefs with littleor no alteration: with microcofmic fait it runsinto a colourlefs globule, with borax it forms alight brown glafs. Its component parts areSilex - ■ _ 63
Alumine - 23
Oxyd of iron 1.25Water - - 12
99.25
It abounds in the ifland of Cimola (whenceits name) now called Argentiera, and washighly valued by the Greeks and Romans forits detergent properties •, at prefent its ufe isalmoft entirely confined to the inhabitants ofthe ifland. When triturated with a little waterit forms a foft pap-like mafs, and being appliedin this ftate to filk or woollen cloth, and allowedto dry on, it abforbs all the greafe which theymay contain, like fullers’ earth, but more effec-tually, and is again difcharged by a flight waffl-ing, leaving the cloth reftored to its originalIuftre.
CINNABAR, Native. See Mercury , Ores
of.
CITRIC ACID. Acid of Lemons . Ztfro -nenfaure, G.
Lemon juice is known univerfally to be oneof the foureft, and at the fame time the moftagreeable of all the native vegetable liquors. Itis prepared limply by fqueezing the fruit, andftraining through linen or any other loofe filter.In Sicily, Italy, Majorca , and many other partsof the Mediterranean, lemon juice forms animportant article of commerce. It is procuredfimply by peeling the fruit, Hieing it, and put-ting it in a large prefs with a cloth or hairftrainer. 1 The juice, which comes out veryturbid, is placed for a day in cellars and thenftrained, and put in jars with narrow neckswell cemented up, the top of the juice beinggenerally covered with a little oil, the better todefend it from the aCtion of the air. Many of theprefles will fqueeze fix thoufand lemons at once.
Lemon juice is a natural mixture, about thefpecific gravity of, 1.034, compofed of muchwater, of infipid vegetable mucilage, of extrac-tive matter, of a flight portion of fomething thatgives an aftringent tafte, of a little malic acid,and laftly of that peculiar acid, which, from itsbeing contained more copioufly in this fruitthan in any other, is called the citric acid. Theproportions of thefe ingredients mull of courfevary according to the degree of ripenefs, b thefeafon, and the like, but on an average accordingto Prouft, 576 grains of the frelh juice lofe byevaporation 528 grains, which is the waterypart •, and of the remaining 48 grains about 30grains are the pure citric acid, and the remain-der is chiefly mucilage and extract. On ac-count of thefe two latter ingredients, lemon-juice fooner or later, according to the tempera-ture, fpoils by keeping, becomes mouldy,undergoes an imperfect fermentation, and atlaft totally lofes its acidity, acquiring a flat muftytafte.
To prevent this deftruCtion of the acid forwhich alone this juice is valuable, many me-thods of prefervation have been devifed, all ofwhich anfwer to a certain degree, but none ofthem perfectly, except that of feparating theacid in a cryftallized form by means which willbe prefently mentioned. It fhould be obfervedthat of the mucilage and the extractive matter,(the'two materials which principally contribute tofpoiling the juice) the former alone is leparableby the ordinary methods of clarification, butthe extraCt adheres to the acid with the greateftobftinacy, and it is this which hinders it from
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