46 PLANT DISEASE 



the total obtained from some specimens of 

 the Calisaya bark. In the larger and thicker 

 rusty crown he found from 2% to 3% of alka- 

 loids, chiefly cinchonidia, but also more or less 

 quinia. In the yellow and red crown varieties 

 he also found cinchonidia associated with traces 

 of quinia and cinchotannic acid. A very fine 

 specimen of fixe crown yielded iJ-% of cin- 

 chonidia and quinia with much cinchotannic 

 acid ; but on an average, specimens of this bark 

 only yielded him from 0-50% to i% of alka- 

 loids. According to the British Pharma- 

 copoeia 20 grains of pale cinchona bark should 

 yield not less than i grain of alkaloids. Speci- 

 mens of pale bark from India yielded Howard 

 varying proportions of alkaloids thus from 

 about 4*30% to 6-40%. 



In Dictionary of Applied Chemistry, by 

 Thorpe, vol. ii. p. 714. Under " Nux Vomica 

 examined by this method " 



Bombay seeds gave from 3-14 to 3*90% 



Cochin 3*04 to 3*60% 



Madras 274 to 3*15% 



Of total alkaloids D and S. 



