Pioneer Labourers 17 



If, for instance, we were to burn a hundred grains of 

 wheat so thoroughly that nothing but ash remained, 

 we should find the whole amount of this to be equal to 

 about two of the grains, or less ; while if we were to 

 take peas or beans, the amount in a hundred of each 

 would be equal to less than three peas, and less than 

 four beans. 



There would be more in the straw or stems of all 

 three kinds of plants, but still the quantity appears so 

 small that one might doubt its being absolutely essential 

 if one did not know that it was so. 



However, ' many a mickle makes a muckle,' and 

 when we consider, not single plants or a handful of 

 grain, but a whole crop, the amount of mineral matter 

 becomes large enough to look important. Thus, while 

 a pinch or two of dust might represent the entire 

 amount of ash of all sorts in a single turnip or carrot, 

 there are, on an average, about 40 pounds of lime alone 

 in 22 tons of turnips, more in proportion in the carrots, 

 and very much more in an equal weight of clover. 



The mineral substances chiefly taken up by plants 

 are sulphur, phosphorus, silica, potash, soda, lime, iron, 

 magnesia, manganese, together with mineral compounds 

 of the two gases chlorine and fluorine. All these are 

 contained in the rocks ; but the question is, How are 

 they to be made available — how is the plant to get 

 hold of them ? There is abundance of food, but as 

 long as it is stored in the rocks it might as well be 

 locked up so far as most of them are concerned, for 

 they cannot get at it or make use of it. Of course,' we 

 all know that seeds cannot grow, though they may 

 sprout, upon a slab of bare stone, even though it may 

 be rich in the very food they want. The stone must be 



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