78 GROWTH AND SECRETIONS. 



such as Asparagin, whose name denotes its origin 

 from the asparagus. 



53. Besides the above, substances are found 

 in plants which are purely mineral, and which 

 are principally lime, magnesia, silica, alumina, 

 and perhaps barytes. Potash and soda are found 

 in very large quantities. Iron, manganese, and 

 copper* have been observed, and besides the 

 above there are occasionally found in plants 

 chlorine, iodine, sulphur, and phosphorus. The 

 reader is referred to No. 4 of these little trea- 

 tises f for further particulars on the chemical 

 part of the subject. 



54. Those whose leisure permits, and whose 

 inclination leads them closely to examine into 

 the simple yet marvellous chemistry by which 

 compounds, absolutely essential to the animal 

 economy, but which it has no direct power of 

 preparing for itself, are formed for it in the 

 vegetable organism, will perceive how true it is 

 that the more we search into those phenomena 

 which we daily and hourly witness and experi- 



* Copper was found by M. Bischoff, Dr. Meissner 

 and M. Sarzeau. See De Candolle, Phy. Veg. vol. i. 

 p. 389. 



t " Introduction to Organic Chemistry." 



