15 



Slope. You need not send any more just at present, for if these three 

 colonies do well this valley will soon be well supplied." 



FERTILIZING AND FERTILIZERS HOW TO COMPOUND 



FORMULAS. 



Having mentioned the use of fertilizers and their wonderful effect 

 upon plant life, I deem it but just to describe the different elements 

 which are the most essential to plant growth, together with the best 

 methods .of compounding them, although most of our soils possess the 

 desired elements for plant growth. 



POTASH. 



Potash is the element potassium combined with oxygen " potassium 

 oxide," it is called by the agricultural chemists. Potassium itself is 

 but a curiosity of the laboratory, for it can be kept pure only by 

 excluding all air, and is therefore only to be found in the bottle of the 

 chemist. The name " potash " was given it because it was made in iron 

 pots from ashes. 



Potash is a most caustic, biting alkali, dissolving and decomposing 

 all organic structures it comes in contact with. It is one of the most 

 powerful bases; in other words, it is a vigorous, unprincipled chemical 

 thief, seizing upon and absorbing into itself the acids it finds combined 

 with various saline compounds. Pure water could not dissolve the 

 potash as it exists in the particles of feldspar and mica that are found 

 in the soil; but, taking carbonic acid from the air, it has the power of 

 dissolving the silicate of potash, leaving the quartz and alumina to form 

 the clays. Caustic lime also has this power. The silica, combined with 

 the potash, and marrying the lime, sets the potash free. In the vege- 

 table kingdom it is held by plants while in the process of growth, in a 

 soluble state, combined with oxalic, tartaric, silicic, and sulphuric acids. 

 When wood is burned, these acids are decomposed; and, the potash com- 

 bining with carbonic acid, we have the common form of carbonate of 

 potash. Potash is not only one of the three essentials for all plant 

 growth, but it is also found in the fruits, vegetables, and grains. 



HUMUS. 



There is a value in barn manure, in addition to its fertilizing prop- 

 erties. Its bulk has a mechanical effect on the soil, improving heavy 

 soils and lightening the texture of all soils a fact of especial value to 

 market gardeners in their early crops. By its partial decomposition, it 

 adds to the mass of dark brown earth which we so especially notice in 

 old gardens, and which goes under the name of humus. Humus is 

 dead vegetable and animal matter in process of decay. In good soil, 

 there is, in a latent condition, potash, phosphoric acid, and lime. Car- 

 bonic acid changes these into plant food. Now, humus, by its decay, 

 develops carbonic acid, and so brings about the decomposition of this 

 latent food. Wet weather favors this action. That carbonic acid lias 

 this power to set free plant food in the soil has been proved by the 

 experiments of Professor Stockhardt. Crops take up only a small por- 



