CHEMISTRY OF PLANTS. 



CHAPTER II. 



ON THE ORGANIC ELEMENTS. 



SECTION I. 



OF THE ASSIMILATED BODIES. 



8. THE four elementary bodies*, Carbon, Oxygen, Hydrogen, 

 and Nitrogen, are associated together as organic or vegetable 

 elements, but they have evidently different values for the life of 

 the plant even in its simplest forms. Next to these we find a 

 series of bodies, which are necessary for the origin and develop- 

 ment of cells, and these I call especial assimilated matters. 



9. Some of these are substances of which the cell-membrane 

 is formed, or which necessarily precede the formation of it, and 

 which contain only Carbon, Hydrogen, and Oxygen. I shall 

 mention here: 1. Cellulose, or Sclerogen; 2. Amyloid; 3. Vege- 

 table Jelly; 4. Starch; 5. Gum; 6. Sugar; 7. Inulin; 8. Oil 

 of Fat. 



1. Cellulose (Sclerogen, Lrignine, woody fibre) is completely formed, 

 rather tender, flexible, and elastic, perfectly clear and transparent, and 

 entirely insoluble in all known menstrua. When treated with caustic 

 potash or concentrated sulphuric acid, starch is formed. Like all 

 organic substance it is distended by moisture and contracted by drying. 

 It is permeable to all fluids and actual solutions, which, under some cir- 

 cumstances, are taken in on one side and passed out on the other. Its 

 composition, when analysed, gave the following results : 



From the wood of the willow and the beech, 

 according to Prout 



r c H o 



1 12 8 8 

 112 11 11 



Various cell-membranes, according to Payen f C H O 

 (Ann. des Sc. Nat. 1839; \ 12 10 10 



These analyses differ only in the quantity of water they contain. 



To me it appears most correct to use the above formula, in which the 

 carbon is reckoned at 12. Mulder, however, takes C 24, H21, O21, as 

 isomeric with soluble inulin. Crookewitt has pointed out that this does 



* Vier Elemente 



Innig gesellt 

 Bilden das Leben, 

 Bauen die Welt. 

 Four elements 

 Intimately mixed 

 Give form to life, 

 Build up the world. 



The genius of the poet has here evidently anticipated later chemical discoveries, 



