424 



MONTHLY JOURNAL OF AGRICULTURE. 



tions to chemical affinity, the vital principle, 

 electricity, or any other force. Agriculture is 

 none the less a chemical art. If we wish to 

 know in what circumstances a plant will best 

 thrive, it is necessary that we -Bhould ascertaui 

 its appropriate food ; and, in order to this, what 

 method is likely to be so accurate and effectual 

 as the chemical analysis of tlie plant itself and 

 the sources whence its food is drawn ? Everj- 

 plant is composed of the elements of matter 

 which must have been drawn from the atmo- 

 sphere, frojn water, or the soil. Transforma- 

 tions have certainly taken place : what was be- 

 fore in the soil or the atmosphere is now a part 

 of the plant, and nothing is found in the latter 

 that has not been received from the former. If 

 we look into the plant, we see w^hat is essential 

 to its nutrition ; if we examine the soil, the 

 water, and the air, we ascertain whether these 

 contain its ai»propriate food : if they do, the 

 plant should thrive without manures ; if not, it 

 is necessary to know the composition and action 

 of manures, before its appropriate food can be 

 inteUigently supplied. Hence we arrive at the 

 conclusion that before we can determine with 

 scientific precision what is necessary in a given 

 place, in order that any plant may be grown 

 successfully, we must know — 



1st. The composition of the plant; 



2d. The composition of the air and water; 



3d. The composition of the soil ; 



4th. The composition of manures. 



The composition of the atmosphere and water 

 in their normal state may be considered con- 

 stant. Hence, when their constituents have 

 been once con-ectly ascertained, farther analy- 

 sis may be dispensed with ; but as to plants and 

 soils and manures, their composition varies with 

 time and place. Here it is, especially, that Ag- 

 riculture requires the aid of Chemistry. Not 

 only must the composition and chemical rela- 

 tions of the atmospheric elements, oxygen, ni- 

 trogen, carbonic acid, ammonia and water, be 



determined — not only must the composition of 

 all plants and of every part of each plant be ac- 

 curately analyzed— but the varjing and com- 

 plicated nature of soils and manures demand 

 the highest powers of chemical analysis. Hu- 

 man genius may here find an ample field for its 

 exercise. The territory is large and compara- 

 tively unexplored. Davy. Liebig,Boussingault 

 and Johnston have surveyed it — have carried 

 through it the compass and the chain ; marked 

 its grand divisions and described its general fea- 

 tures. A century of human effort will hardly 

 complete what they have begun — will fail to 

 open and cultivate the ground which they have 

 as yet but just surveyed. 



To illustrate the views we have attempted to 

 offer, as to the relation of Chemistry to Agricul- 

 ture, we will briefly consider one or two of our 

 most valuable crops. The following table gives 

 the general composition of wheat and oats, ac- 

 cording to Boussingault : 



TABLE I Composition of Wheat and 



Oats. 



Composition. 



Carbon 



Oxygen... 

 Hydrogen 

 Nitrogen . . 

 Ash 



Total. 



Wheat. 



Oats. 



Confining our attention at present to the four 

 elements, oxjgen, carbon, hydrogen and nitro- 

 gen, it may be observed that they compose es- 

 sentially the whole plant, except the ash, which 

 is the product left after combustion. Combining 

 with each other in different proportions, they 

 form all those nutritive compounds, such as glu- 

 ten, starch, albumen, sugar and the like, which 

 give value to the crops. Hermbstadt sowed ten 

 patclies with the same seed of each crop, and 

 applied a different manure to each patch. The 

 seed produced in each instiince vi'ere analyzed, 

 and the foUovsing tables give tlie results : 



TABLE II Shov/ing the Composition of Wheat a.vd the Effects of Manures. 



ISfi] 



