ISO LECTURES ON 



starch and gluten, the latter often crystallized. In leguminous seeds 

 q accumulates; while in the exterior portions of most seeds occur 

 cells containing, in addition to these bodies, numerous droplets of 

 fixed oil.— (See the figures already given.) Some cells are largely 

 occupied with coloring matter, which is green in leaves, red. yellow, 

 &c, in petals. In many cells we meet with crystals of salts; some are 

 ounds of vegetal acids with lime and magnesia: others are phos- 

 phates and sulphates. 



In every plant, and in each cell, there may he found, by chemical 

 analysis, though generally not by the microscope alone, a certain, 

 never-failing content of mineral matters, which remains as ash when 

 the vegetable is burned. The ashes of all agricultural plants contain 

 the following mineral matters, to which in the table are appended 

 their chemical symbols: 



Ingredients of the ash of plants. 



m 7 . (Potash KO 



^"«s \ Soda Xa 



, 77 7 . , 7 (Lime Ca 



Alkaline earths, j Magnesia Mg 



, r , -,-,. , ( Oxvd of iron Fe„ 0, 



he oxyas • ■< ^ * ■, ,. „„„„„„ at,," r> 



I Oxyd ot manganese Jln 3 U 4 



Carbonic - C0 2 



Sulphuric S0 3 



Phosphoric P0 5 



__ Silicic Si 3 



Chlorine % - CI. 



These matters taken together form but a small part of the plant — 

 lly from one to five per cent, of its weight — yet they are indis- 

 pensable to its development, as is evident from their constant presence, 

 and as has been likewise proved by the most careful and extended 

 synthetic experiments. Without the co-operation of all these earthy 

 and saline matters it is impossible for plants of the higher orders to 

 develop themselves. 



The Prince Salm Horstmar, of Brunswick, has made the function of 

 the mineral food of the plant the subject of a most extended and 

 laborious investigation. In experiments with the oat he found that 

 when silica was absent from the soil, everything else being supplied, 

 the plant remained smooth, pale, dwarfed, and prostrate. 



Without lime the plant died in the second leaf. 



Without potash or soda it reached a height of but three inches. 



Without magnesia it was very weak and prostrate. 



Without ph. - acid it remained very weak, but erect and of 



normal figure, bearing fruit. 



Without sulphuric acid it was still weaker: was erect and of normal 

 figure, but without fruit. 



Without iron it was very pale, weak, and disproportioned. 



Without manganese it did not attain perfect development, and bore 

 but few flowers. 



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