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.
685/796 (page 659)
![density of CsCl, (Scott, Pr. E. 1888), and also by comparing the salts with those of the other alkali metals. The salts of Cs are very similar to those of Eb ; they are well marked, stable, compounds; no basic salts are known ; so far as investigation has gone the Cs salts show a marked tendency to form double salts. Most of the salts of Cs are soluble in water; the solutions are ppd. by PtCl4Aq (yellow), by H2.C4H406Aq (white), by HC10.,Aq (white), and by silicotungstic acid (white). The chief salts are carbonates, nitrate, selenatcs, silicotungstate, sulphates, tartrate (v. Carbonates, &c). M. M. P. M. CAFFEIC ACID C„H„04 i.e. [4:3:1] C6H.,(OH),.CH:CH.CO,H. Di-oxy-cin- namic acid. Di-oxy-phenyl-acrylic acid. Formation.—1. By boiling caifetannic acid with aqueous KOH (Hlasiwetz, A. 142, 221).— 2. From its acetyl derivative.—3. Powdered cuprea bark is extracted with ether followed by alcohol; the residue is boiled with aqueous KOH, H2S04 is added, and the liquid filtered while hot. The filtrate, when cold, is exhausted with ether, and the ethereal solution, after de- colourising with animal charcoal, is set aside to crystallise (G. K6rner,P7i. [3] 13, 240).—4. From hemlock (in which it is combined with con- hydrine?) (Hofmann, B. 17, 1922). Properties.—Yellow monoclinic tables (con- taining £aq), v. e. sol. alcohol. The aqueous solution is turned green by Fe.^Cl,;, on adding NaoCOj it then changes to blue and violet. It does not reduce Fehling's solution but reduces warm ammoniacal AgNOs. Its solution in KOHAq turns brown in air. Reactions.—1. Dry distillation gives pyro- catechin.—2. Potash fusion forms protocate- chuic acid.—3. Sodium amalgam reduces it to di-oxy-phenyl-propionic acid. Salt s.—CaA'., 3aq.—SrA'„ 4aq.—BaA'., 4aq. Ba,(CaH504)., 9aq.—Pb.((C9H50.i), 2aq. Mono-methyl derivative v. Ferulic ACID. Di-methyl derivative C(H.)(OMe)2.CH:CH.C02H. [180°]. Formed by saponifying the ether or by heating caft'eic or ferulic acid with Mel and KOH. White needles. Sol. alcohol and ether, nearly insol. water. On oxidation with KMn04 it produces veratric acid. Methyl ether A'Me. [64°]. Prisms. Pre- pared by methylation of isoferulic acid (Tie- mann a. Will, B. 11, 651; 14, 959). Methylene e ther CH2<^>C6H,.CH:CH.C02H. [232°]. Formed by boiling piperonal CH.,0.,:C6H1.CHO with NaOAc and Ae.,0 (Lorenz, B. 13, 757). Minute crystals (from dilute alcohol). Cone. H..SO, forms a brick-red solution.—AgA'. Acetyl-methyl derivative v. Acetyl- FERULIC ACID. Di-acetyl derivative C13H,(OAc)2CH:CH.CO,H. [191°]. Fromcaffei'c acid and Ac.,0 or by heating protocatechuic alde- hyde (2 pts.) with NaOAc (2 pts.) and Ac.,0 (0 pts.). Slender needles. V. si. sol. water, v. sol. alcohol and ether (Tiemann a. Nagai, B. 11, 659). Hydro-caffe'ie acid v. Di-oxy-phenyl-pro- PIONIC ACID. CAFFEIDINE C;H12N,0. Formed, together with methylamine, C02, and NH3, by boiling caf- feine with cone, baryta-water (Strecker, A. 123, 360 ; 157, 1; G. B. 52, 1269 ; Schmidt, B. 14, 816; Schultzen, Z. 1867, 616). Alkaline liquid. Sol. water, alcohol, and chloroform, si. sol. ether. Long boiling with baryta-water gives methyl- amido-acetic acid, formic acid, C02, and NH:l. Chromic acid oxidises it to di-methyl-oxamide, methylamine, CO.,, and NH3 (Maly a. Andreasch, ill. 4, 381). EtI forms C-HHEtN,0. Salt s.—B'HCl.—B'.,H„PtCl,. 4aq. CAFFEIDINE CARBOXYLIC ACID CgH.oN.O.^. Prepared by the gradual solution of caffeine in dilute NaOHAq; this solution is neutralised with HOAc and the copper salt ppd. with Cu(OAc)., (Maly a. Andreasch, ill. 4, 369). Very soluble crystalline mass ; its aqueous solu- tion on boiling gives off C02 and leaves eaffeidine. Salts.—KA': golden syrup.—HgA'./iHgCL,: bulky pp.—CuA'.,: minute crystalline granules.— CaA',.—ZnA'„.—CdA'2.—MgA'2. CAFFEINE CKH,0N4O... Theine. [23050]. S.G. 12 1-23. S. 1-35 at 16°; 45-6 at 65° (Com- maille, C. B. 81, 817). S. (alcohol) -61 at 16° ; 3T2 at 78°. S. (ether) -044 at 16°. S. (CS.,) -06 at 16°. S. (chloroform) 13 at 16°. Occurrence.—1. In coffee berries and leaves (Runge, Materialicn zur Phytologie, 1820 ; Sten- house, P. M. [4] 7, 21; Pfaff a. Liebig, A. 1, 17). Coffee berries contain from 1 to 1*28 p.c. caffeine; roasted coffee about 1*8 p.c. (Paul a. Cownley, Ph. [3] 17, 565 ; cf. Stenhouse a. Campbell, C. J. 9, 33; A. 89, 246).—2. In tea leaves (Oudry, Mag. Plmrm. 19, 49; Jobst, A. 25, 63; Mulder, P. 43, 160). Tea contains 2 to 4 p.c—3. In guarana, the dried pulp of Paulinia sorbilis (Martius, A. 36, 93). Guarana contains about 5 p.c. of caffeine.—4. In Mate or Paraguay tea the leaves and twigs of Ilex Paraguayensis (Sten- house, P. M. [3] 23, 426).—5. In the seeds of the Kola tree (Cola acuminata) of West Central Africa, to the amount of 2-13 p.c. of the dried seed (Attfield, Ph. [2] 6, 457).—6. Present to a small extent in cocoa (E. Schmidt, A. 217, 306). Formation.—By heating silver theobromine with Mel for 20 hours at 160°: caffeine is thus shown to be methyl-theobromine (Strecker, A. 118,151; E. Schmidt, A. 217, 282). Preparation.—1. Tea or coffee is exhausted with boiling water; tannin is ppd. by lead sub- acetate ; the filtrate is freed from lead by H2S and evaporated to crystallisation (Peligot, A. Ch. [3] 11, 129).—2. Raw ground coffee (5 pts.) is mixed with moist lime (2 pts.) and extracted with alcohol, chloroform, or benzene, from which the caffeine crystallises on evaporation (Vers- mann, Ar. Ph. [2] 68, 148; Vogel, C. C. 1858, 367; Payen, A. Ch. [3] 26, 108; Paul a. Cownley, Ph. [3] 17, 565).—3. Tea or coffee is boiled with water and either the whole, or else the filtrate, is evaporated to a syrup, mixed with slaked lime and extracted with chloroform (Aubert, PflUger's Archiv, 5, 589 ; Cazeneuve a. Caillol, Bl. [2] 27, 199).—4. By sublimation from tea (Heiynsius, pr. 49, 317).—5. A de- coction of tea is evaporated with PbO to a syrup, K,C03 is added, and caffeine extracted by alcohol (Grosschoff, J. 1866, 470). Properties.—Mass of slender silky needles (containing aq); begins to sublime at 79° v u2](https://iiif.wellcomecollection.org/image/b21995990_0001_0685.jp2/full/800%2C/0/default.jpg)
