DICTIONARY OF THE ACTIVE PRINCITLES OP PLANTS. 



11 



Mem. — A tannin is contained in the root, giving red colour with potash 

 and green with ferric cliloride. 



§ 2.'>. AR AKIBA rubra (Pickneya rufescens), Rtibiacecr. 



ARIBINE A., C,.,H,,„X_, and with sHoO (Rieth and Wohler, 18G1). Crys. 

 rhombic octahedra or prisms; optically inactive; neutral; bitter; 

 M.P. 2'29° with sublimate ; salts crystalline. 



Soluble in alcohol, with difficulty in amyl alcohol or ether, and requiring 

 7,762 parts of cold water (easier soluble on heating, with deposition of 

 cr^■stals as solution cools). 



Precipitants : 



Alkaline hydrates. 



„ carbonates. 

 Ammonia. 

 [Lead acetate, no pp.] 



[Tannic acid, no pp.] 

 Chlorine water, pp. sol. warm. 

 Bromine water, yel. pp. sol. warm. 

 Iodine tincture, pp. sol. warm. 



Concentrated acids, pp. from solutions 



§ -li. ARBUTUS group ; Siv'cacefP, P?/cfiface"', etc. A. uva ursi (Arcto- 

 sta|ihylos, or Bearberry), («), (/), not {d). Arctostaphylos glauca (Man- 

 zanita), the leaves («). 



f'himaphylla umbellata (Pyrola umbellata = Winter green), (a) not (d). 



Ledum palust7-e (Labrador Tea, or 'James' Tea'), (a) not (rf). 



Cilluna vulgaris («). 



Erica Rhododendron (c) ; Pyrola (c) : Vaecinium (Cranberry ; V. vitis 

 ida?a = Red Whortleberry), (c), ('") ; Azalea Indica, (c), (d) ; Gaultheria 

 (Winter Green, see also above), {c) [no (d) in G. procumbeus] ; Clethra 

 (r:) [Clethra arborea and alnifolia do not contain (d)] ; Eriodictyon, (c) ; 

 Epig»a, (c) ; Rhododendron ponticum, (c), ((/) ; R. chrysanthemum, 

 Hybridum and Maximum, (d) [no ('/) in R. Hirsutura]. 



(d) Also in all the following : Andromeda japonica [also (//), (/')], 

 A. Catesboei, Calyculata, Polyfolia, Angustifolia ; Kahnia Latifolia. 



(d) Is iiol contained in Erica vulgaris, nor in Oxydendron arboreum. 



(a) ARBUTIN G., C.,5H.,jO,j or C,„Hi60-(:-'). Cry.s. silky needles with 2H.,0 ; 

 ls3vo-rotatory ; M.P. 144°-14G°, if previously dried at 100 ; very hygro- 

 scopic ; neutral ; bitter. 



Acids change to sugar and hydroquinone. 



Soluble "in water and alcohol when hot, with difficulty in these fluids 

 when cold, and scarcely in ether. 



Reactions : 



Xiil ]irecipitated by neutral lead acetate nor by other metallic salts. 



Ferric chloride, blue coloration. 

 [Fehling's solution, not reduced.] 

 (h) METHYLARBUTINV,., C,.,H,„0-(?). Similar to Arbutin ; M.P. 142"- 

 14:-i°. Yields sugar and uiethyl-hydroquinone. 



((■) ERICOLIN G., CjjHsiiO.,, ; amorphous brown ; semi-fusion at 10(»\ 

 Removed by benzene from an acid solution. 

 Reactions : 



[Lead acetate, neutral or basic, no pp.] 

 [Tannic acid, no p]i., or but slight.] 

 Gold chloride, no jip., but reduction on warming. 

 [Sliver nitrate, no pp.] 



Concentrated sulphuric acid, yellowish-brown. 

 ,. „ „ with sugar, red. 



t'nihde's solution, brown. 

 Wanned with dilute acid, odour of ericinol. 

 (■■) ANDROMEDOTOXIN (Asebotoxin) B., CnHsiO,,, (de Zaeyer) ; crys- 

 tallizes in needles; M.P. 2211°; hevo-rotatory) but dextro-rotatory in 

 chloroform solution) ; neutral reaction, bitter. Extremely poisonous, 

 more so even than aconitine, and more emetic than emetine or apomorphine. 

 Solubility: lOO parl.K of the respect'ivK solvents take up tlie follotdnrj 

 quanfiiies— venter, 2-Sl at '12" C. 0-87 at 100°; alcohol, 11 -7 at 12° C.'; 

 amyl .ilcohol, 1-14 ; chloroform, (1-26 ; ether, 0-07 ; benzene, 0-004. In- 

 soluble in petroleum ether. 



Reactions : Alkaline hydrates remove the colours produced by acids 

 (on re-.iculif\ing the solution, the colours reappear). 



No precipitates by lead acetate, neutral or basic, nor by usual alkaloid 

 reagents. 

 Concentrated sulphuric acid, dark brown, becoming red on warming. 

 Dilute sulphuric acid solution slowly evaporated, magnificent red — 



resembling narceine reaction (see Opium). 

 Solution in 2;'! per cent, phosphoric acid evaporated with a little 

 hydrochloric acid, red. 

 (e) VACCININ B. (nitrogen free). Crys. in prisms, fusible. 

 Soluble in alcohol and water (crystals from a cooling solution), scarcely 

 in ether. 



(/■) URSON, (A,,|H,jO., (from Arbutus uva ursi) ; crystalline, tasteless; 

 M.P. l'.).s -2O0 , snblimable. 



Soluble with difficulty in alcohol or ether. Insoluble in water, acids, 

 or alkalies. 



