INORGANIC CONSTITUENTS OF PLANTS. 



113 



In 1000 Ibs. of the field Bean, field Pea, and Rye-grass hay, after being dried in 

 the air, the following is the amount of ash, and its composition : 



2136 31-21 



24-64 



49-71 



52-86 



224, Dr. R. D. Thomson gives the following analysis of the inorganic 

 matter in the stem and seeds of Lolium perenne : 



Stem. 



Silica 64-57 



Phosphoric acid 12-51 



Sulphuric acid 



Chlorine 



Carbonic acid 



Magnesia 4-01 



Lime 6-50 



Peroxide of Iron 0'36 



Potash 8-03 



Soda... .. 2.17 



Seed. 



42-28 



18-89 



3-12 



trace. 



3-61 



5-31 



18-55 



2-10 



4-80 



1-38 



225. These substances are variously combined in plants, in the form 

 of sulphates, phosphates, silicates, and chlorides. Some plants, as 

 Wheat, Oats, Barley, and Eye, contain a large quantity of Silica in 

 their straw; others, such as Tobacco, Pea-straw, Meadow-clover, Potato- 

 haulm, and Sainfoin, contain much lime ; while Turnips, Beet-root, 

 Potatoes, Jerusalem-artichoke, and Maize-straw, have a large proportion 

 of salts of potash and soda in their composition. Sulphates and phos- 

 phates are required to supply part of the material necessary for the 

 composition of the nutritritive proteine compounds found in grain. 



226. Silica abounds in Grasses, in Equisitem, and other plants, 

 giving firmness to their stems. The quantity contained in the Bam- 

 boo is very large, and it is occasionally found in the joints in the form 

 of Tabasheer. Eeeds, from the quantity of siliceous matter they con- 

 tain, are said, during hurricanes in warm climates, to have actually 

 caused conflagrations by striking against each other. In the species 

 of Equisetum, the silica in the ash is as follows : 



