1004 FOODS AND FOOD ADULTERANTS. 



SCHIFF. Tannic acid, constitution and formula of. Ber. d. chem. Ges., 1872, 291, 438; 



Bull. soc. chim. [2], 18, 23. 

 SCHIFF, H. Taunic acid, constitution of. Berichte, 1882,2588; Jsb. d. Chem., 1882, 



915. 

 SCHMIDT, E. Tannin, modification of Pribram's method. Jsb. d. Chem., 1874, 1035 ; 



Bull. soc. chim. [2], 21, 256. 



HENHOUSE. Tannin, kinds of. Dingler's polyt. Jour., 165, 150. 

 SONNENSCHEIN. Tannin, action of, on Fehling's solution. Analyst., 10, 205. 

 SIMAND, F. Gelatin, substitute for, in Lowenthal's process. Analyst., 3, 125. 

 TRIMBLE, HENRY. Tannins, the. J. B. Lippincott Company, Philadelphia. 

 ULBRICHT, R. Tannin, notes on Lowenthal's method. Zeitsch. f. anal. Chem., 25, 



252; Ber. d. chem. Gesell. zu Berlin, 18, 1116. 

 VOGL, A. Tannin in the roots of plants. Wien. Acad. Ber., 53, 156; Jsb., d. chem. 



1866, 690. 

 WATTS. Tannin, criticisms on Fleck's method. Jsb. d. Cheni. 19, 887 (1868) ; Pharm. 



J.Trans. [2], 10. 223. 



CAFFETANNIC ACID. 



HLASIWETZ. Caffetannic acid, derivatives of. Ann. Chem. Pharm., 142, 219; Bull. 



soc. chim. [2], 9, 122; J. pr. Chem., 101, 97. 

 KRUG, W. H. The separation and estimation of caff'etannic acid. Original article 



in this report, page 908. 

 LIEBICH. Caffetannic acid, action of KOH on. Jsb. d. Chem., 1849, 324; Ann. 



Chera. Pharm., LXXI, 57; Pharm. Centralhalle, 1849, 855. 



BIBLIOGRAPHY OF METHODS FOR THE ESTIMATION OF CAFFEINE. 



ALLEN, A. H. A thin dough is made of the powdered tea, caustic lime, and water 

 and the whole allowed to stand several hours. It is now dried on the water- 

 bath, extracted with benzole, the benzole evaporated and the caffeine re- 

 crystallized from water. Chem. News, 29, 129, 140, 167, 189, 221; 30, 2. 



BEEKMAN. The material is extracted with water containing a little sodium carbon- 

 ate. The aqueous extract is mixed with an alum solution, the excess of 

 alum precipitated by sodium carbonate and the precipitate filtered off. The 

 filtrate and washings are evaporated to a syrupy consistence, made alkaline 

 with sodium carbonate, and the caffeine extracted with ether. Zeitsch. f. 

 anal. Chem., 4, 206. 



BLYTH, A. W. This method is based on the ease with which caffeine sublimes. 

 The author proceeds as follows : From one to two grams of finely powdered 

 tea are boiled with water for an hour in a flask connected with an upright 

 condenser. The whole is transferred to a porcelain dish, about its weight of 

 magnesia added, and the mass evaporated nearly to dryness. It is now trans- 

 ferred to an iron subliming plate and covered with a tarred glass funnel, the 

 edge of Avhich i.s accurately ground and which has a neck several inches 

 long. The mixture is first heated to 110 C., then slowly raised to 200 C. and 

 finally to 220 C. The caffeine sublimate is collected and weighed. Ana- 

 lyst, 2, 39 ; also in Foods : Their Composition and Analysis, A. W. Bly th. 



CANADA, DOMINION OF. Ten grains of the finely ground sample are exhausted by 

 repeated boiling with water, filtered, the filtrate made up to a definite vol" 

 lime, and an aliquot part precipitated with basic acetate of lead. The filtrate 

 without any concentration is shaken with successive portions of chloroform. 

 The chloroform is removed by distillation and the caffeine is weighed. Re- 

 port on Adulteration of Food, Supplement III, Report of the Dept. of Inland 

 Revenue, 1886. 



CAZENEUYE-CAILI.OL. Add to the tea four times its weight of boiling water and when 

 the leaves become soft add an equal weight of slaked lime. Dry and extract 



