118 Fertilizers 



tion. Unless it has been thoroughly exposed to the air, 

 it contains small amounts of acetylene gas which is in- 

 jurious to seeds. It should be exposed to the air before 

 using or applied to the soil a few weeks before planting. 



Oxy-acetylene residue. 



Occasionally oxy-acetylene residue is to be had for 

 fertilizer purposes. It is another by-product from the 

 manufacture of gas, but it should not be confused with 

 calcium carbide waste because its principal ingredient is 

 potash rather than calcium. It contains from 45 to 55 

 per cent of potash in the form of the muriate, a high per- 

 centage of which is soluble in water. 



Purchase and use of miscellaneous materials. 



There are a vast number of miscellaneous fertilizing 

 materials left unmentioned in the foregoing. For the 

 greater part such materials are only used in localities 

 where they may be secured at little or no cost outside of 

 the cost of labor for hauling and distribution. In general, 

 miscellaneous materials are very bulky and are not con- 

 centrated in the elements of plant-food even though the 

 constituents may be contained in forms valuable for plant- 

 feeding purposes. In many cases the indirect effect upon 

 the physical condition of the soil is quite as valuable as 

 the plant-food contained, as it is the case with green sand 

 marl so extensively used in New Jersey at one time. The 

 same is true of peat and muck. If the material is con- 

 centrated and offered for sale, it is always advisable to 

 purchase only upon analysis or guarantee. This is true 

 in the case of most materials which may be had at little 

 cost because often they will not return the cost of carting 

 and handling. 



