MANURES AND THEIR APPLICATION. 313 



the soil until it is converted into nitrate, and then it flows down 

 easily through the soil and subsoil. 



Nitrate of soda, apart from its manurial properties, has, like 

 lime, a very beneficial action upon the physicial condition of 

 the soil and subsoil, tending to open it up and make it more 

 porous. 



There is a very common belief that nitrate of soda is not, 

 properly speaking, a manure ; some call it a stimidant, and con- 

 sider that its function is simply to exhaust the land — a kind of 

 purge which does not itself contribute to the making of a crop. 

 This is a very inaccurate view to take of the action of nitrate 

 of soda. I have already explained that all nitrogenous matter 

 in the soil is being converted into nitrate, and in this form 

 it is taken up by roots. In manuring with nitrate of soda we 

 simply give to the soil nitrogenous plant-food ready made and 

 in larger quantity than can be supplied by the soil itself 

 durinf? the time in w^hich it is wanted. If the addition of this 

 nitrogenous food causes a large increase in the crop, that is a 

 sifin that there is a want of nitrocfenous matter in the soil, or 

 that what is there is not being rapidly enough decomposed. 

 Thus when a soil is rich in pliosphate and other mineral plant 

 food, but the plant is unable to make use of these for the want 

 of nitrogen, the mere addition of nitrate by presenting the plant 

 with the nitrogenous food it requires enables it to take out of 

 the soil all the other constituents it requires for its growth. It 

 is said that nitrate of soda has been applied to some soils until 

 they have been reduced to poverty. That is no doubt a mis- 

 fortune for the land, but it is not because of the addition of 

 nitrate that the land has suffered, it is because phosphates 

 and perhaps potash and other manurial matters were not added 

 in due proportion. If a man becomes reduced to a state of 

 bodily poverty from eating nothing but potatoes, it is not the 

 potatoes that are to blame ; they have done their best ; it is 

 the want of the concomitant roast beef or other nourishini^ 

 food. 



Coming now in this very cursory sketch to the various forms 

 of phosphatic manure, whose employment in ever increasing 

 quantity has during these latter years done so much to alter the 

 whole conditions of agriculture, I will endeavour to be very 

 brief. The form of phospliatic manure which first was tried in 

 this country w^as bones — and that was just about half a century 

 a.ijo. Tliey rapidly rose into favour, and have never lost tlie good 

 opinion that was formed of them. The old method of using 

 them has happily fallen into disuse. It was customary for a good 

 many years to use half-inch bones, which meant fragments of 

 bone in size from two inches downwards. I have seen some of 

 these which had been sown about fifteen years before, turned up 



