177 



To agricultural chemistry and such works as those of Wolff, in 

 Europe, and Professor Hilgard, of the University of California, we 

 owe a great deal of the knowledge we at present possess, respecting 

 the: 



MINERAL CONSTITUENTS OF THE ASHES OF VARIOUS PLANTS. 



The above table taken from a paper on orchard manures by 

 Mr. H. C. L. Anderson, M.A., formerly Director of Agriculture, 

 N.S.W., gives an insight into the composition of the ashes of 

 18 of the most extensively cultivated fruits. Thus says Mr. 

 Anderson : Run down the column of figures under potash and see 

 how widely the percentages differ the ashes of peaches containing 

 nearly 75 per cent, of that mineral (potash), and the ashes of apples 

 not half as much. Then look at the figures under phosphoric acid, 

 and see how they vary, from nearly 44 per cent, in the ashes of 

 almonds and quinces down to less than one-fourth of that amount 

 in grapes, and less than one-fifth in olives. 



The other columns are not deserving of special attention, and 

 are given merely to convince the student that the substances lime, 

 magnesia, and iron are of lesser importance when compared with 

 potash and phosphoric acid. 



In practice four only of the fourteen mineral contituents of 

 plants are, in the majority of cases, supplied to the crop under the 

 form of fertilisers, and these are nitrogen, potash, phosphoric acid, 

 and lime; the first three especially are the most sparsely distributed 

 in soils and are also the most costly to replace. 



With every crop of fruit removed from the orchard the avail- 

 able stores of postash, phosphoric acid, and nitrogen in the soil are 

 correspondingly diminished. 



