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ter may be afterwards separated from the liquid by a solution of tin, and is very little inferior to the other.

Carnelian. A sub-species of calcedony.

Caromel. The smell exhaled by sugar when exposed to a strong heat.

Carrying Power. If heat be applied to the upper surface of liquids, it makes its way downwards by what is called the heatconducting power of bodies, and which is found in solids as well as in fluids; but when it is applied to the lower part of fluids, these portions of them grow, specifically lighter, and rise to the top, while other portions take the lowest place, to be heated in their turn. This is called the carrying, or transporting power of fluids, and was first accurately examined by Count Rumford.

Carthamus, bastard saffron, s»ffiower, Spanish red, China lake. A pigment obtained from the flowers of a plant cultivated in Egypt, principally for the sake of its flowers. It is used for dyeing silk of a poppy, cherry, rose, or orange red. Rouge also is prepared from Carthamus. The red colour is extracted by a solution of subcarbonate of soda, and precipitated by lemon-juice. The precipitate is dried on earthen plates, mixed with talc, or French chalk reduced to powder. The fineness of the powder and the proportion of the precipitate constitute the difference between the finer and cheaper rouge.

Cartilage. About one third of the bones of animals is composed of an clastic semi-transparent solid substance, which has received the name of cartilage. It resembles coagulated albumen: it is that portion of the bones which is first formed, and in-which the earthy matters that give firmness to these organs are deposited. A deficiency of these latter, or their absorption into the system, is the cause of the disease called rickets. As the phosphate of lime gives bones their strength, go cartilage gives them

toughness and flexibility. Cartilage seems gradually to decrease and disappear as animals grow old.

Case Hardening. A process1 which gives to iron the hardness of steel, while it retains its own toughness. The instruments to be case-hardened are, before being quite finished, put into an iron box with powdered charcoal, and kept for a short time exposed to a strong heat, which converts the outer part into a coating of steel. The heated pieces are then immersed in water, and afterwards polished by the usual methods.

Caseic Acid. The hame given by Proust to an acid he found in cheese, and to which he ascribes some of the properties of this substance.

Cassava, jatropha manihat. A curious American plant, containing a pleasant food and a deadly poison. The roots are squeezed, the starch or food remains, while the juice, which separates, is used to poison arrows. Even this juice gradually precipitates starch, which is perfectly wholesome. The root itself, till thus prepared or cooked, is poisonous ; but when either boiled or prepared and dried, makes a very good bread, which is used for food.

COTTON MANUFACTURE.

The quan tity of cotton converted into yam in Great . ■. • Britain and Ireland in one lbs. year is about 160,000,000

The loss in spinning may be

estimated at ljoz. per lb. 13,000,000

Quantity of yarn produced 145,000,000 Amount, supposing I8d. to betheaverage price per lb. £10,875,000

According to Mr. Kennedy's calculation, that every person employed in spinning produces 900lbs. per annum, the number of persons employed is 161,111.

The number of spindles employed, supposing each to produce 15lbs. per annum, is 9,666,666.

The capital invested in buildings and machinery, cannot be less than 18,000,0001.

QUEMES.

To the Editor of the Chemist.

Sir—Observing in No. XXV. of yourinteresting.little Work, the cornmunicatioiLjejf T. Z. on a method of decomposing water by means of 'galvanic electricity, I should I:ict' it as a favour if yon or your Correspondent would answer the following Query. Does the decomposing power of the galvanic battery depend on the size of the plates fir on the number of series? Your Correspondent gives, a description of a simple apparatus for collecting the gases in a separate state; I take the liberty of inclosing another more complex, but very convenient, which, if it meets your approbation, you may, perhaps, insert in a future Number. I remain, Your obliged, &c.

J. R. S.

Sir,—Permit me to ask the best method of obtaining the gold from washings which are produced from old frames or other gilt work, in the business of carving and gilding (as it is usually called, to distinguish it from water-gilders.) The mode of proceeding with work which is to be regilt, is to wash the old gold off with a piece of cloth and water; it is then put in a pan, and when settled, the water is poured off, leaving the dischargings behind, which are dried and sold; but many pounds have been thrown away for want of knowing how to extract the gold from it. If, Sir,; you will inform me the best me^* thod, by any chemical or' other process, you will much oblige a. constant reader of your paper.

- Yours, most obediently* ., ••
■ • In the dark,

Sept. 1st,' . j •■■..-,• Olivbiu. ...

Se,

HEAVY And LIGHT WATERv

TAKE>two portions of the same water, and colour each of thenr differently, by means of any two of the substances mentioned at page 397 of the Chemist. Let one of these portions be heaited while the"

other remains cold. If the hot water be then poured gently into a glass jar containing the cold water, it will remain on the surface and scarcely mix with the cold water; but if the cold water be poured on the hot it will sink to the bottom of the vessel; showing, that the specific gravity of the same body may be decreased or increased by the effect of heat.

TO CORRESPONDENTS.

The present Number completes the First Volume of The Chemist, and it was consequently our intention to publish a Supplemental Number next week, containing the Index, Preface, <$•<;., but zee tire obliged to delay it for a few weeks, from being unable to 'get the engraving ready with which the Supplement is to be ornamented.

The communication o/James Wright has been received, ana will be inserted Mf our next.. -j^/. j^

Juvenis is informed that we'do_ not consider the Bible to be authority in. matters of science.. Every theory, either of tight or of any.other phenomena, must be substantiated by facts' before it can be described as mcontestibly proved. The passage which he' quotes has given rise to a vast deal of discussion, and philologists are not yet decided as to Vs meaning. He will see, therefore, we should suppose, ut"ence, tkejnutilityjnf framing a theory of'the. whole universe on an obscure phrase ina bookwhich is admired from our being unable to comprehend it. This will, tec hope, be a satisfactory reason why we do not -insert his letter. At the same time, ive agree with him, that no que*- tions which are not plainly above the power of,man to solve should ever be regarded-at excluded from' our 'researches." j«,. , i.

"••«• Communications (post j be addressediq.iheXdiior^ik the". Ushers''. ■'■■ "W; ■>■•,»•».' . -

London: Publishedby Knight and Iiii-"

'.' ... y.* "rt*W'

Cey, 55, Paternoster-row.—Printed bj/ B. Bensley, Bolt-court, Fleet-sheet.

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AesoftbiSlG, cascade for, described 274
Acetate of lime, phosphorescence of 175

Acetic acid, test for 194

and pyroligtioUs acid, the

same 265

Air of apartments, how purified.. 281
— atmospherical, effect of, on

life......... .......332 349

Alcohol, how to obtain it pure.... 442

properties it.

Alchymists, a history of one .... 7

— trick of one ..,,.,.. 23

——i' i,"'. \. language.of 38

Alkalies. See potash', soda, and

ammonia.

— vegetable 39 55

Alumina, an earth, described .... 180

Aluminum, a metal it.

Amalgamation, process of, de-
scribed 298

Ammonia, spontaneous formation

of 391

«^ subcarbooate of, how

prepared 321

-~——- sulphate of 398

Animals, influence of sound on .. 72

-—■ — heat of, how generated.. 333

Ant-hills 142

Ants, vinegar of 144

Antimony, how prqcured........ 340

———— nature and properties 341

———- curious effect of, on

gold it.

Apparatus, chemical, described.. 50
Arbor Diana;, how made......... 334

Arsenic, tests for. 12

effect of, on iron ..,..'. 318

[blocks in formation]

Page
318

13

339

Mo

301
421
301
102

88

Babmgtohite, a newly discovered

mineral 68

Baltic, level of 32

Balloon, Lana's, described ....... 401

Bark-tree, some account of,..... 271

Barlow, Mr. his discovery as to the

mariner's compass explained .. 231
Barometer, extraordinary fall of 270

— an infallible one..263 307

■ ■ a musical one de-
Scribed. 397

an injudicious mode

of making 421

Beccher, biographical notice of .. 119
the connecting liuk be-
tween alchymists and chemists it.

Beds, air..... 37

Bergman,-an eminent Swedish

chemist, biographical notice of .189
Bismuth, how and where obtained 283
—-—■— subnitrate of, a medicine 392

Bleaching, history of '34

; early practised in Egypt it-

m. i ■—extensively in Home 35

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