Volume 1
Watts' dictionary of chemistry / revised and entirely rewritten by H. Forster Morley and M.M. Pattison Muir ; assisted by eminent contributors.
- Date:
- 1888-1894
Licence: Public Domain Mark
Credit: Watts' dictionary of chemistry / revised and entirely rewritten by H. Forster Morley and M.M. Pattison Muir ; assisted by eminent contributors. Source: Wellcome Collection.
Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.
689/796 (page 663)
![CAINCIN C„,H64019. Catncic acid. S. -14. Found in Cainca root (from Chiococca anguifuga and racemosa) (Francois, Pelletier, a. Caventou, J. Ph. 16, 405; Liebig, A. Ch. [2] 47, 185; Eochleder a. Hlasiwetz, A. 76, 338 ; Eochleder, J. pr. 85, 275). The root is exhausted with alcohol and the ca'incin ppd. either by milk of lime or Pb(OAc),. Crystalline flakes, tasteless at first, afterwards very bitter ; v. si. sol. water and ether, v. sol. alcohol; reddens litmus. Boiling alcoholic HC1 splits it up into a sugar (06H,j06) and crystalline caincetin C22H3403. Caincetin is resolved by potash-fusion into butyric acid and caincigenin 0MHj402 which is possibly related to aiscigenin. Ca'incin in dilute alcoholic solution is converted by sodium- amalgam into crystalline C3liH5(,0ls whence fuming HC1 forms gelatinous C]sH.H0.,. CAJEPUT, OIL OF. A light green oil pre- pared in India by distilling the leaves of Mela- leuca leucodendron with water. Its chief con- stituent is cineol C1(JHlaO (q. v.), which is also called cajeputol. Pj05 converts it into ter- penes (q. v.) which when so obtained may be called cajeputenes (Schmidt, C. J. 14, 63; Wright a. Lambert, C. J. 27, 619; Histed, Ph. [3] 2, 804; Blanchet, A. 7, 161; Gladstone, G. J. 49, 621). CALAMUS ROOT. According to Geuther (A. 240, 92) the acorin prepared by Thorns (p. 60) from Acorus calamus is not a definite substance, but is separated by alkalis into a neutral amorphous brown mass (C.1(lH(i7N07 ?) and an acid (CnH1!(03 ?). Calamus root after extraction with water still contains a combined acid (CnH1804?) which may be extracted by adding HC1 and shaking with ether. When the root is distilled with steam, methyl alcohol and a mixture of terpenes (q. v.) and a compound C,0HlljO(?) is obtained (G.; Schnedermann, A. 41, 374 ; Kurbatow, B. 6,1210 ; Gladstone, C. J. 17, 1). CALCIUM. Ca. At. w. 39-91. Mol.w. unknown. Melts at red heat. S.G. 1-57 (Matthiessen, A. 93, 27). S.H. (0°-100°) -1686 (Bunsen, P. 141, 1). S.V.S. abt. 25. E.C. (Hg at 0° = 1)12-5 (Matthiessen, P. M. [4] 12, 199 ; 13, 81). Chief lines in emission-spectrum, 6121-2, 5587'6, 4226-3, 3968, 3932-8. Occurrence.—Never free. Very widely dis- tributed, and often in large quantities, as silicate, phosphate, sulphate, carbonate, flu- oride, &g. Most natural waters contain Ca salts; phosphate and carbonate of Ca are found in plants and animals. Ca salts occur in the sun, fixed stars, and meteorites. Calcium carbonate and burnt lime have been known from very ancient times. In 1722 Fr. Hoff- mann showed that lime is a distinct earth; Black (1755) was the first to make a quantita- tive examination of limestone and burnt lime. In 1808 Davy obtained calcium (impure) by the electrolysis of lime. Formation.—1. Dry Cal2 is heated with Na in an iron crucible with an air-tight cover (Lies-Bodart a. Jobin, A. Ch. [3] 54, 363; Dumas, C. R. 47, 575 ; Sonstadt, C. N. 9,140).— 2. Dry fused CaCl, (300 parts), Na (100 parts), and pure distilled granulated Zn (400 parts), are heated in a crucible with loosely fitting lid, as high a temperature being maintained as is possible without volatilisation of much Zn ; an alloy of Ca and Zn is thus produced (Zn,.,Ca according to v. Bath, P. 136, 434). This alloy is heated in a crucible of gas coke until the Zn is all distilled off (Caron, C. B. 48, 450 ; 50, 547).—3. A boiling cone, solution of CaCl, is electrolysed, using an amalgamated Pt wire as negative electrode (Bunsen, A. 92, 248). Preparation.—A mixture of dry CaCl;. and SrCI,, in the ratio 2CaCL:SrCl,, mixed with a little NH,C1, is melted in an open crucible ; the current from 3 or 4 Bunsen cells is passed through the molten mass, the positive electrode being a stick of carbon, and the negative an iron wire as thick as a knitting needle, drawn out to a fine point. The point of the iron wire is kept just under the surface of the molten mass for a minute or so at a time ; the Ca separates in small lumps (Matthiessen, A. 93, 277; 94, 108). Frey obtained lumps of Ca weighing from 2,j to 4 grams (A. 183, 367); he passed the negative electrode through the stem of a tobacco pipe with the bowl dipping under the molten mass in the crucible ; H was then passed into the pipe; when the pipe and bowl were filled with this gas, the H was stopped, and the current was started; the Ca rose into the bowl of the pipe, and being in contact with H remained quite unoxidised. Properties.—Lustrous, clear yellowish-white, very ductile, but brittle when hammered out, malleable ; about as hard as calcspar. Frey (A. 183, 367) says it is brittle and cannot be hammered out or drawn into wire. Melts at full red heat, and then burns with yellow flame and production of much heat and light; [Ca, O] = 130,930 (Th. 3, 251). Does not oxidise in dry air; but in ordinary air is quickly covered with CaO. Not volatilised at temperature of inflam- mation (Caron, C. B. 48, 440). Decomposes cold H.,0 rapidly; [Ca, Aq] = [Ca, O2, H'-', Aq] - 2[H2,0] = 80,900 (Th. 3, 251). As no compound of Ca has been gasified, the value to be given to the atomic weight of the metal is decided partly by the S.H. and partly by purely chemical considera- tions. The mass of Ca that combines with 15-96 (i.e. with 1 atom) O is 39 91, hence the simplest formula for the oxide is CaO (Ca = 39-91); the same mass of Ca combines with 2 x 35-37 CI, 2 x 7975 Br, &c.; the simplest formulae for the chloride and bromide are there- fore CaCl., and CaBr, respectively (Ca = 39-91). These formula? are in keeping with the reac- tions of the compounds, hence they are adopted. The chief compounds of Ca by analyses of which the value Ca = 39-91 has been found are : (1) CaCl, (Berzelius, O. A. 57, 451; Dumas, A. Ch. [3] 55, 190); (2) CaCO:, converted into CaO (Dumas, C. B. 14, 537 ; Erdmann a. Marchand, J. pr. 26, 472). Ca is a strongly positive metal, forming well-marked and stable salts by replacing the H of acids. Salts of Ca derived from almost every acid are known; several of these form double salts; very few basic salts are known. CaO,H, is an alkaline hydroxide ; CaO combines with H,0 with pro- duction of much heat; CaO.JI, is dehydrated to CaO at a high temperature. [CaO, H O] = 15,540 (Th. 3, 251). The heat of neutralisation of CaO^HjAq is the same as that of KOHAq,](https://iiif.wellcomecollection.org/image/b21995990_0001_0689.jp2/full/800%2C/0/default.jpg)
