CHAPTER I. — THE CELL. 141 



Among the better known non-volatile alkaloids are aconitinc 

 (C^H^NO^), obtained from Aconitum napellus ; brucine, (CjjHj, 

 N 2 4 ), obtained from the seeds of Strychnos nux-vomica ; caf- 

 feine (C 8 H 10 N 4 O 2 ), obtained from Coffee, Guarana and Tea ; qui- 

 nine (C^H^NjOj), obtained from the Cinchona barks ; morphine 

 (C 17 H 19 N0 3 ), obtained from the milk-juice of the Poppy ; and 

 strychnine (C 2 iH 22 N 2 2 ), obtained from the seeds of various spe- 

 cies of Strychnos. 



Nicotine (C 10 H U N 2 ), obtained from Tobacco ; Conine (C 8 H 15 N), 

 obtained from the Poison Hemlock ; and sparteine (C 8 H I3 N), ob- 

 tained from the Broom, are examples of volatile alkaloids. 



Amides not Alkaloidal. Not all the amides found in plants 

 have the nature of alkaloids. Some possess no alkaline reaction ; 

 and moreover are not in the nature of waste products, but 

 sustain important relations to the life of the plant. Among 

 the more important of these are asparagin (C 4 H 8 N 2 3 ), found 

 in Asparagus, Marsh-mallow, Eunonymus, the Leguminosse, 

 and in many other plants ; glutamin (C 5 H 10 N 2 O 3 ), found in 

 the Beet ; and tyrosin (C 9 H n N0 3 ) and leucin (C 6 H 13 N0 2 ), both 

 found in germinating seeds. They occur in solution in the cell- 

 sap. Asparagin is one of the forms in which nitrogenous matters 

 are transferred from one part of the plant to another. Reserve 

 proteid is changed into it and transferred to growing parts, 

 where it is again converted into protoplasm. It is probable 

 that the others mentioned have similar uses. 



Unorganized Ferments. These are nitrogenous com- 

 pounds whose chemical nature is not well understood, but they 

 appear to be closely related to the proteids. Their peculiarity 

 consists in their power to bring about important chemical changes 

 in substances with which they are in contact. On this account, 

 they are of great importance in the economy of vegetable life. 

 In their nature and action they are similar to the animal fer- 

 ments, ptyalin, pepsin and trypsin. Some of them, as diastase 

 and ma/tin, which occur in germinating cereals and also else- 

 where in plants, have the power to convert starch into dextrine 

 and grape-sugar ; others, as emu/sin, found in bitter almonds and 

 some other seeds of rosaceous plants, and myrosin, found in the 

 seeds of black mustard, have the power to decompose glucosides 

 with the formation of grape-sugar; a ferment called invertin, 

 found in yeast, has the power to change common cane sugar into 



