CULTIVATED MOWING-LANDS. 143 



consequently there is enough given in the leached ashes. He 

 has virtually wasted the extra amount in the unleached ashes. 



Capt. Moore. I think, if you will call upon Professor 

 Goessmann, he will give you a solution of this jiroblem ; and 

 it will probably be -this, — that some soils in Massaclmsetts 

 need potash, and some do not. 



Professor Goessmann. The question has been already 

 answered in part ; but I think we might take a broader 

 ground. The principle on which vegetable growth is found- 

 ed is the principle of restitution. If the soil has not j^otash, 

 the plant which needs it will not grow. If a potash fertilizer 

 added to the soil does not make an impression upon the crop, 

 it shows that potash is not wanted. One thing is sure, — and 

 that is the only thing that is sure, in connection with this 

 question, — the essential constituents of plants cannot replace 

 each other. There are six or seven substances which are 

 essential to plant-growth : if one is wanting, the rest cannot 

 operate. This applies to lime as much as to potash ; to phos- 

 phoric acid as much as to nitrogen. In our plant here, we 

 find the potash is the larger proportion of the saline con- 

 stituent. Wherever- that plant grows, it must find some 

 potash. In this case, undoubtedly, the soil already contained 

 a sufficient amount of potash to supply the quantity required 

 to produce the growth : without it, it would not have grown. 

 The question is, Where did it come from ? Of course, the 

 name " leached ashes " is a collective name, and applies to a 

 variety of materials : sometimes merely the potash has been 

 abstracted ; sometimes the ashes have received a certain 

 amount of lime. The potash which the ashes contain may 

 supply the amount required for the growth of the plant. 

 But there comes in another point. If the leached ashes have 

 received an addition of lime — lime is a material which may 

 set free potash ; and upon clayey soil the application of lime 

 not only supplies the lime for the plant, but it is a j)owerful 

 disintegrator of the constituents of the clay. The clay 

 originally came from a rich potash compound, granite. 

 When that clay is only in part decomposed, then, of course, 

 the lime may elaborate a large quantity of potash from the 

 soil ; and this is an advantage of the latent resources of plant- 

 food in the soil. If, therefore, these leached ashes operate as 

 has been stated, there are two causes possible, — either that 



