ASPAEAGIN. 



365 



example, the petioles of the cotyledons). That the source of the 

 asparagin must be the re.serve albuminous matters in tlie seed, 

 appears from the following consideration : " The absolute amouut 

 of nitrogen remains the same during germination, and the 

 nitrogen of seeds is all or nearly all contained in their albumi- 

 nous ingredients." ^ Asparagin and the chief proteid of the 

 seeds in leguminons plants have been thus compared : — 



"Asparagin contains less carbon and hydrogen but more 

 oxygen than legumin and other proteids. Consequently if the 

 whole of the nitrogen of legumin is used in the formation of 

 asparagin, a considerable quantity of carbon and hydrogen must 

 be given off and a certain amount of oxygen absorbed. Exactly 

 the opposite will take place upon the conversion of asparagin 

 into proteid." ^ 



961. Products contaiDiug nitrogen. III. The alkaloids. These 

 substances all possess the power of uniting with acids to form 

 salts, and they are often described as basic alkaloids. Among 

 the most important are Morphia, Quinia, and Strychnia. 



The number of alkaloids now known is very great, and the 

 modes in which they are found combined in the plant are very- 

 diverse. They are more abundant in those plants which are 

 grown under conditions of considerable warmth, and are much 

 more abundant in some parts of the plant than in others, as is 

 shown by the case of morphia. Nothing is positively^ known as 

 to their origin or proper function in the organism. It should 

 be mentioned, however, that many of them when applied to 

 the very plants from which they were prepared prove to be 

 poisonous ; thus, morphia poisons the poppy. 



962. Frodacts containing nitrogen. IV. Unorganized ferments. 

 It has long been known that there must exist in certain parts of 



1 Pfeffer, in Sachs's Text-Book, 1882, p. 719. For a full account by Pfcffer, 

 see Pringsheim's Jahrbiicher, viii., 1872, p. 429 ; and Monatsbericht der Ber- 

 lin Akadeniie, 1873, p. 780. See also Husemann and Hilger: Die Pflauzen- 

 stoffe, i., 1882, p. 264. 



