644 



SCIENTIFIC AND APPLIED PHARMACOGNOSY 



Emetine (methyl-cephaeline) is white, amorphous, forms crys- 

 talline salts, becomes darker on exposure to light, and with Froehde's 

 alkaloidal reagent (consisting of 0.01 gm. of sodium molybdate in 

 1 c.c. of concentrated sulphuric acid) becomes dirty green, changing 

 to a bright green on the addition of hydrochloric acid. Cephaeline 

 occurs in silky needles, forms amorphous salts and is quite unstable, 

 becoming yellow even in the dark. With Froehde's reagent, ceph- 

 aeline changes to purple, becoming deep blue on the addition of hydro- 



kf 







FIG. 286. Rio ipecac: T, tracheids; P, parenchyma containing starch; S, 

 starch grains; Ca, raphides of calcium oxalate. 



chloric acid. Psychotrine is amorphous, quite unstable, and becomes 

 purplish with Froehde's reagent, changing to green on the addition 

 of hydrochloric acid. Ipecac also contains 2.25 per cent of ipe- 

 cacuanhic acid, with which the alkaloids are combined; a glucoside 

 resembling saponin; about 40 per cent of starch; and calcium oxalate 

 in the form of raphides. 



The total amount of alkaloids in Rio and Cartagena ipecac not 



only varies, but there is a difference in the proportions of emetine 



the expectorant alkaloid) and cephaeline (the emetic alkaloid); in 



Rio ipecac the proportion is one-third cephaeline to two-thirds erne- 



