114 QUARTERLY JOURNAL. 



a? animal substances from decay. And it is probably on this ac- 

 count that it has been found useful in propagating plants from 

 their cuttings. Many remarkable experiments have been made 

 with it, and with great success. Even leaves have taken root in 

 finely powdered charcoal, kept constantly wet. 



INORGANIC ^(PARTS OF PLANTS.— STRAW AS A MANURE. 



Besides the four substances which we have often mentioned — 

 oxygen, hydrogen, nitrogen and carbon — as forming what are 

 called the organic elements of plants, a number of others are al- 

 ways found in them, which they derive from the earth; and these 

 have been called inorganic. They are all of mineral origin, being 

 produced by the decay of rocks, of which they form a component 

 part. We have said, they were always found in plants, and this 

 is strictly true — they being as absolutely necessary for the produc- 

 tion of a perfect plant as those first mentioned. But the quan- 

 tity is not at all times the same, nor the same in all parts of the 

 plant. Thus, during one period of its growth, one substance, as 

 potash, may be found to abound ; whilst, at another period, the 

 relative proportion of this particular substance will be found to 

 have "fery much diminished. And the whole proportion of inor- 

 ganic matter may be very different at one period from another. 

 Thus it was found that " plants of the same wheat, which a month 

 before flowering, left 7 . 9 per cent of ash, left when in flower, 

 only 5.4, and when ripe 3.3 per cent" — (Johnston) — showing 

 a remarkable diminution in the quantity of ash, or rather, perhaps, 

 increase in organic matter. 



Different parts of the same plant exhibit, also, a very material 

 difference in the same respect, and presenting a very strong prac- 

 tical bearing to the farmer. We shall refer to this below. The 

 fact is shown by the analysis of the straw and grain of different 

 plants. According to Springel, whose analyses are thought to be 

 very correct, when 1000, lbs. of wheat straw are burned in the 

 open air, 35.18 lbs. of ash are left. When the grain itself is 

 burned, 11.77 lbs. are left. We give some of the most remarka- 

 ble differences between the quantities of inorganic substances, of 

 which this ash consists, in the following table : 



