Lecture-Notes on Chemistry for Dental Students; Including Dental Chemistry of Alloys, Amalgams, Etc., Such Portions of Organic and Physiological ... of Dentistry, an Inorganic Qualitative - Softcover
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1906 edition. Excerpt: ... in the addition of oxygen but in the withdrawal of hydrogen; thus the oxidation of methyl alcohol produces formaldehyd (CH2O) and water. CH3OH + O = CH2O + H2O. Aldehyds may be considered compounds containing an H H / I alkyl radical and a distinctive group,-C;thus CHO is for O maldehyd, CH3, in acetaldehyd, etc. (compare Alcohol, page CHO 131). Formaldehyd coagulates albumen and hardens gelatine; when used as a preservative it renders the proteids tougher and less digestible. Formaldehyd polymerizes, producing the paraform or paraformaldehyd of trade, trioxymethylene, with a probable forula of (CH2O)3. It also forms one lower polymer (CH2O)2 and at least one higher, formose, a substance allied to glucose. Acetaldehyd, aldehyd, CH3-CHO or C2H4O, the aldehyd from ethyl alcohol, may-be made by addition of H2SO4 to a mixture of alcohol and bichromate of potassium. It is a colorless, inflammable liquid with pungent etherial odor and boils at 22 C. Paraldehyd, (C2H4O)3, a polymer of acetic aldehyd, is a "colorless liquid with a strong pungent odor, soluble in 8.5 parts of water at 15 C, miscible in all proportions with alcohol, ether, and fixed or volatile oils." (U. S. P.) It is a valuable hypnotic. Chloral, CC13CHO, trichloraldehyd, is an oily liquid formed by action of dry C1 gas on pure alcohol; soluble in ether and chloroform, boiling at 94 C to 98 C, and forming, with a molecule of H2O chloral hydrate, CCl3CHO.H2O, a crystalline solid, and this is the "chloral " of the pharmacopoeia (see page 111). Chloral hydrate is decomposed by caustic soda or potassa with liberation of chloroform (see Exp. 20, p. 142): CC13-CHO+KOH=CHCl3 + KCOOH (potassium formate). Upon warming a drop or two of aniline oil an excess of alcoholic potash...
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