100 MASSACHUSETTS HORTICULTURAL SOCIETY. 



applied to the same land without the use of animal manures. And 

 the same may be said of the use of fertilizing salts. 



They are good in their season ; but animal manures are indis- 

 pensable. All plants, except fungi, require alkalies and alkaline 

 earths. The^' must be supplied with both organic and inorganic 

 matter, and that, too, in a condition for use. They feed in a 

 mysterious waj', on infinitely small particles, and have a choice of 

 these. They select from among the particles of inanimate matter 

 the parts they need, and which will combine and assimilate only 

 under fixed conditions and limitations. The}' refuse, during life, to 

 obey the chemical laws which govern organic matter, but after 

 death they become subject to them, and dissolve accordingly. 

 While they live and grow, they appropriate and organize inorganic 

 matter. They never directly absorb organic matter, and yet they 

 cannot grow in a soil without it. A good soil will contain about one- 

 fifth part in weight of such matter ; but the plants will drink only the 

 gases, and wait for the dissolution of the compounds. The volatile 

 portions of all their reserves are the most valuable, and water helps 

 to generate them and retain them for use. It brings to them 

 carbon and ammonia in right proportions. Rain mechanically 

 opens the earth anew, and sweeps awa}' the useless and inert air 

 and other matter, with some noxious compounds, making room 

 for, and introducing new and fresh reinforcements. Electricity, 

 light, heat, air, and water are continuaUy working for us in a way 

 incomprehensible, but always by fixed laws, the observance of 

 which laws when known tends vastly to our advantage. As I have 

 said, organic matter must be always at command in the soil, and 

 there is no better way of supplying this organic matter than by 

 mixing peat with ayiimal manures. These manures not only tend 

 to modify the mechanical texture of the soil, but they furnish 

 carbonic acid and ammonia, or nitric acid, and the earthy and 

 saline compounds required by plants. The}"^ assist in the decom- 

 position of the vegetable matter, while the absorbing peat seizes 

 and retains all their most volatile parts, one-half or two-thirds of 

 which might otherwise escape. It has been estimated that one cord 

 of animal manure, properlj' composted with peat, will make four 

 times its original value in good manure. 



As ammonia is the natural food of plants, the best manure is 

 that which will produce and retain the greatest amount of nitrogen, 

 which is the base and principal ingredient of ammonia. If nitrogen 



