FERTILIZERS. 35 



about one-fifth to the quantity given. It appears to be 

 the settled conviction among men of science, as the results 

 from many experiments, that plants cannot take up pure 

 nitrogen directly from the air. The theory is, that they 

 are able, to a greater or less degree, to get their supply 

 through the water, that carries it in some form in solution 

 into the soil, and also from the air indirectly, by the soil 

 first separating it from the air that permeates it. Still 

 another source of natural supply for plant-growth is nitro- 

 gen in a latent condition, that has accumulated in the soil> 

 set free by the action of such substances as lime and 

 plaster. There is a general belief among agriculturists, 

 that plants have ways of collecting nitrogen still but little 

 known ; while some extremists have gone so far as to de- 

 clare that there is no necessity of feeding nitrogen to our 

 crops, for they can of themselves collect from natural 

 sources all they require. There is a growing belief that 

 their power to supply their wants from natural sources 

 is greater than has hitherto been credited to them. It is 

 found, also, that different kinds of plants have different 

 capacities for taking up nitrogen. Clover is an example ; 

 for, though nitrogen enters largely into its composition, it 

 has such a capacity to help itself to the good things which 

 surround it, that it needs but very little artificial help 

 from the manure pile : while wheat, though it needs but 

 little nitrogen, is so dainty a feeder that it insists on a 

 large artificial supply, from which it may pick out that little. 



WHERE NITROGEN OR AMMONIA COMES FROM. 



THE WASTE OF THE FISHERIES. One of the prin- 

 cipal sources from which manufacturers obtain the am- 

 monia in their fertilizers is from the fish waste or offal 

 which they pick up all along the Atlantic coast, from 

 Maine to Florida. The largest portion of the waste is 



