54 WILSON & TOOMKIl FKKTILIZER COMPANY 



sects. About one-third of kainit is common salt, hence 

 its burning properties. 



Canada Hardwood Ashes carry a small content of pot- 

 ash in most desirable form, and about 33^ per cent, basic 

 lime. They are expensive as a source of plant food and 

 neutralizer, but owing to their physical form often have 

 a peculiar and beneficial effect on the soil. At times noth- 

 ing else will quite take the place of ashes. 



Land Plaster or Gypsum This is sulphate of lime, 

 which is fully described under Superphosphate. 



Acid in Fertilizers Several letters have come to me 

 asking if it is true that "ordinary fertilizers contain from 

 100 to 150 pounds of free acid in a ton." For the benefit 

 of those who have not written, I will say, no chemist 

 w r ould uphold such statement. Fertilizers are either neu- 

 tral or practically neutral when applied, and have acid 

 or alkaline tendencies according to the portion base or 

 radical used by the plant. Often the alkaline tendency 

 of one material balances the acid tendency of another 

 in a formula, some formulas being quite alkaline in their 

 general effects. It is true that practically our only 

 source of potash and only slow-acting source of ammonia 

 for citrus trees have acid tendencies, but since this can 

 be easily and cheaply counter-balanced by limestone, we 

 need feel no concern. We also may bear in mind that 

 most of our soils w^ere acid before they ever had a pound 

 of fertilizer, while as to the fertilizer, did it contain 

 free sulphuric acid, the bags, tools, and hands of the 



