THE VOLATILE PAET OF PLANTS. 121 



to be more abundant in dark than in light -colored oats, 

 and, when present to the extent of more than nine-tenths 

 of one per cent, to act as a decided nerve-excitant on ani- 

 mals fed mainly on oats. Avenin is described as a gran- 

 ular, brown, non-crystallizable substance, but neither 

 Osborne (at the Connecticut Experiment Station) nor 

 Wrampelmeyer ( Vs. St., XXXVI, p. 299) have been able 

 to find any evidence of the presence of such a body in oats. 



Morphin, C 17 H 19 N0 3 , occurs, together with several 

 other alkaloids, in opium, the dried milky juice of the 

 seed-vessels of the poppy cultivated in India. Its use in 

 allaying pain and obtaining sleep and its abuse in the 

 "opium habit" are well known. 



Piperin, Ci 7 H 19 N0 3 , the active principle of white and 

 black pepper, is a white crystalline body isomeric with 

 morphin. 



Quinin, C 20 H 24 N 2 2 , is the most important of several 

 bases used as anti-malarial remedies obtained from the 

 bark of various species of cinchona growing in the forests 

 of tropical South America, and cultivated in India. 



Strychnin, C 2 iH 22 N 2 2 , and Brucin, C 23 H 26 N 2 OH, is 

 the intensely poisonous alkaloid of nux vomica (dog 

 button). 



Atropin, CnH 2S NO s , is the chief poisonous principle 

 of the " Nightshade" or belladonna, and of stramonium 

 or "Jamestown weed." 



Veratrin, CgoH^NOg, is the chief toxic ingredient of 

 the common White Hellebore, so much used as an 

 insecticide. 



Solanin, C 42 H 87 N0 15 (?), is a poisonous crystalline 

 alkaloid found in many species of Solanum, especially in 

 the black nightshade (Solanum nigrum). It occurs in the 

 sprouted tubers and green fruit of the potato (Solanum 

 tulerosum) and in the stems and leaves of the tomato 

 (Solanum lycopersicum). 



The alkaloids, so far as investigated, appear to be more 



