Proceedings of the Faemers' Club. 349 



the substances that enter into tlie composition of vegetation, enable 

 us to better avail ourselves of those laws aiicl to more readily supply 

 those substances to the plant. Chemistry, like every other depart- 

 ment of practical science, only tells us how me may act in accordance 

 with nature. For instance, we are treating a soil that is sterile after 

 a liberal appropriation of manure, we puzzle over the reason until an 

 analysis shows the presence of copperas, a poison to plant as to animal 

 life. Without further information we might be at a loss to remove 

 the poison and renovate the soil ; but the chemist, aware that lime will 

 displace the oxyd of iron from its combination with sulphuric acid, sug- 

 gests the use of that mineral, not as a manure, but as a chemical agent, 

 and the problem is solved. The noxious substance is changed to harm- 

 less sulphate of lime and inert oxyd of iron, and crops grow thriftily, 

 where thc}^ refused to sprout before. A similar illustration may be 

 found in another use of lime, in the reclamation of swamps and 

 peaty lands. Research has made known the existence in such soils 

 of acids derived from organic decay, and not only hurtful to plants, 

 but locking away from their reach the ammonia that would other- 

 wise feed them. The chemist explains that lime attacks these com- 

 pounds, neutralizes the acids, and liberates the ammonia, so that the 

 scientific farmer, turning against Nature the force of her own laws, 

 makes available by art for the benefit of his crops the substance that 

 the natural chemistry of the earth had cunningly hidden from their 

 reach. Chemistry not only tells how, in these and a hundred other 

 ways, we may change and ameliorate the condition of the soil, but 

 tells why and wherefore some soils are naturally better than others. 

 For instance, when we learn that clay has the power of absorbing 

 and preventing the washing away of certain soluable substances, and 

 of abstracting from their solutions potash, ammonia, phosphoric acid, 

 and other manurial agents, we can easily understand how it is that 

 the productiveness of an argillaceous soil should be more stable and 

 permanent than that of a sandy one through which the fertilizing 

 matter will filtrate away, Not only does the art of the chemist thus 

 in a great measure enable us to judge of the capabilities of the soil, 

 to change its condition, and to trace the progress of its elements as 

 they are transformed by the weird agencies of organic life, but it 

 goes still further than this. It enables us, as well to seize these ele- 

 ments, some of them as volatile as the air we breathe, and to hold 

 them fast until we are ready to apply them to the ground. Thus it is 

 that knowing the sliarp and odorus vapor that rises from dung-heaps 



