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laid on new bricks which abforb much of theirmoifture, and make them hard enough to beftoved. Here the ftarch remains in a moderateheat, till a flimy cruft rifes to the furface, whichis carefully fcraped off, and the reft, which isnow perfectly pure ftarch, is papered.and placedagain in the ftove with a good hot fire, till quitedry. This laft ftoving caufes the lumps to crack 'pretty uniformly into the fmall pieces in whichthey appear when fold. The Jlimes are alltreated in the fame way till all the ftarch is gotfrom them. All the refufe matter from ftarchmaking makes very valuable food for fatteninghogs, The whole time of making ftarch, fromthe firft fteeping of the wheat to the laft ftoving,is about fix weeks ; and 551 Winchefter bufhelsof wheat will make about fix ton of ftarch. Thiswill be about -j 7 y of the entire weight of thewheat.
In the procefs of ftarch-making a great quan-tity of a lour naufeous milky water is obtained,from which the ftarch fubfides after it is firftremoved from the fermenting vat. This hasbeen analyzed with great care by Vauquelin,with the following relults.
This liquor has an acid, and at the fame timea fpirituous flavour, it ftrongly reddens litmus,gives a precipitate with lime-water, which anc-xcefs of the liquor-re-difloIves. Alcohol addedto it gives a white, light, foft precipitate. Ox-alic acid alfo gives a precipitate, which fhewsthat the acid contained in the liquor is not theoxalic.
A quantity of this liquor was diftilled. The-firft'produft-was fenfibly fpirituous, and yieldedon- rectification a notable quantity of pretty purealcohol. After this, an acid-liquor came over,which gave a fait refemb'ling exactly acetite oflead when faturated with litharge, acetite oflime, with lime, and therefore was acetous acid.The refidue in the retort, after molt of the liquorhad diftilled off, was reddilh-brown, had a veryfour tafte mixed with that of burnt bread, and afyrupy confidence. It was filtered, and theclear liquor gave with-lime-water an abundantprecipitate, which an excefs of the liquor re-difl’olved with cauftic alkalies a fimifar preci-pitate was alfo formed, along with an obvious •production of ammonia and with oxalic acid,oxalat of lime was produced. With the folu-tions of lead a white precipitate fell-down, andthis latter decompofed by fulphuric acid, gaveanother acid which in every refpect agreed withthe phofphoric.
The ftarch-fours therefore contain, befides a
vifible white matter feparable by filtering, a
quantity of pbofphat of lime and ammonia,both held in lolution by the acetous acid which'is generated fo abundantly by the fermentation.A peculiar animal matter is alfo found in this'acid liquor, which feerns to refemblc gluten, andtherefore which only belongs to that ftarch’which is made from wheat flour.
- This liquor therefore contains the five follow-ing fubftances, viz. acetous acid, ammonia,alcohol, gluten, and pbofphat of lime, but ofthefe only the two laft are natural to the wheat;the others are the products of the fermen-tation, the ammonia being generated by the de-compofition of part of the gluten, the alcoholby the faccharine mucilage which all grain con-tains, and the acetous acid perhaps from all theother principles. The peculiar office which this'acid performs in ftarch-making is to diffolve'the gluten and pholphat of lime, and thus tofeparate them from the pure ftarch. Hence'when wheat is the-grain employed, arifes theneceffity of continuing the fermentation longenough to generate a fufficient quantity of ace-tous acid ; for the other grains and roots which ■yield ftarch contain little or no gluten. A con-fiderable quantity however of the ftarch mull;'be deftroyed in the procefs, for wheat contains'much more of it than is- obtained in mami- •fafture, as-may be found by w-afhing flour parte 1with water in the way mentioned in the- begin--nin-g of- this article,-
STAURQLITE. Granatite, Sauffure and-
Its colour is reddifh or blackiflr-brown. It -occurs always cryftallized. The form of itscryftals is a hexahedral prifm, of which fourfaces- are by much the largeft and meet in pairs,forming two obtufe oppofits angles, meafuriiig1.29 0 . This prifrti is“ either entire or truncated ’on the obtufe angles. It is not uncommon to 'find two cryftals penetrating each other ob--liquely or at right angles, fo as to form a crofs;.fometimes even three prifms are thus arranged,forming a triple crofs. Its furface is frtiooth :or uneven, and its luftre varies accordingly. .Internally it is more or lefs fhining, with a :luftre between vitreous and refinous. Its frac-•ture parellel to the axis is imperfe&ly lamellar: ■in the oppofite direction it is fmall-grained un- •even, palling to conchoidal. It is brittle, andfomewhat harder than quartz. Sp. gr. 3.28.
When expofed to the blowpipe it undergoesno other change than that of fritting a little onits furface. Its component parts according toan analvfis by Vauquelin* are