hundred and fifty to five hundred million dollars. 

 Hence the annual productive value of the seven 

 crops above mentioned ia nearly equal to half 

 the value of the ontii'e agricultural and dairy 

 produce of the British Empire, which has been 

 recently estimated at eleven hundred million 

 dollars. If we were to increase the amount 

 given above by the annual produce of the live 

 stock and all the remaining crops of the coun- 

 trj', we .should form a probable estimate of its 

 agricultural wealth. 



May we not, then, be safelj' considered, in 

 the aggregate, a nation of planters ? And is not 

 the cultivation of the soil the ba.tis of our nation- 

 al wealth ? The dignity of the plow should be 

 asserted, and every friend of American great- 

 ness and independence should strive to give ef- 

 ficiency and success to whatever will elevate 

 and strengthen the agricultural interests of the 

 nation. 



We shall next consider how the interests of 

 Agriculture may be subserved in the establi.sh- 

 ment of the proposed Smithsonian Institution. 

 If what we have written above be attentively 

 regarded, it will be duly conceded, we think, 

 that an Agricultural Department^ wide extent 

 should be preeminent among its objects. 



How should such a Department be organized? 

 We propose to answer this question at some 

 length. 



We place among the frst requisites of this 

 Department a well appointed Chemical Hall, or 

 Laboratory. 



Agriculture is a chemical Art. The atmo- 

 sphere which surrounds the growing plant — 

 the water that refreshes and gives it vigor — the 

 soil into which its roots penetrate — the manures 

 that supply it with food — and the plant itself— 

 its roots, stalk, leaves, sap, flowers, and seed — 

 are chemical compounds ; many of them com- 

 plicated in their nature, and having extensive 

 and abstruse relations. If we take the most 

 simple in this composition, atmospheric air and 

 water, we find them composed of oxygen, nitro- 

 gen, hydrogen, carbonic acid, and ammonia, 

 with one or two other bodies which may, per- 

 haps, be considered incidental. These are sub- 

 stances strictly chemical in their nature, and 

 having a range of affinity more extensive than 

 any known in the science. Tlieir affinities em- 

 brace each other, and nearly all other elenienta- 

 rj' and compound bodies. Oxygon, for instance, 

 combines with nitrogen in at lea.st five propor- 

 tions, besides entering into the composition of 

 the atmosphere: also with hydrogen in two 

 proportions— one of which is water, a chemical 

 agent of great extent and influence ; and with 

 carbon, forming two compounds — one of them 

 carbonic acid, sustaining a peculiar and impor- 

 tant relation in the nourishment and growth of 

 plants. Combinations are likewise formed with 



metallic and non-metallic elements by oxygen ; 

 it enters into nearly all compounds of animal 

 and vegetable origin, and has a prominent place 

 among the constituents of the soil and manures, 

 indeed, of all the forms and modifications of 

 matter. 



Air and water, it is thought, contain a large 

 portion of the food essential to the mttrition of 

 plants. Dr. Licbig, in his " Organic Chemistry 

 of Agriculture and Physiology." has said — " Car- 

 bonic acid, ammonia and water yield elements 

 for all the organs of plants. The atmosphere 

 and the soil offer the same kind of nourishment 

 to the leaves and roots. The former contains a 

 comparatively inexhaustible supply of carbonic 

 acid and ammonia ; the latter, by means of its 

 kvmus, generates constantly fresh carbonic 

 acid, while, during the winter, raiii and snow 

 introduce into the soil a quantitj- of ammonia 

 sufficient for the development of the leaves and 

 blossoms." Excepting, then, the inorganic ele- 

 ments, which are supposed by him to be of 

 seoondar3- importance, it is tlie opinion of Lie- 

 big that the constituents we have been consid- 

 ering supply in the fonii of carbonic acid, am- 

 monia and water, the only food of plants. Though 

 this view has been questioned, and, I conceive, 

 justly, by Johnston, it yet remains true by the 

 admission of all chemists, that these three com- 

 pounds act a very important and essential part 

 in the economy of vegetable life. 



Whatever transformations these agents ex- 

 cite or undergo, they seem to be as purely 

 chemical in their nature as the agents them- 

 selves. The carbon of the carbonic acid is taken 

 by the plant, and its oxygen is evolved. So the 

 elements of ammonia and water may be used at 

 the pleasure of the plant. Here nothing is ob- 

 served which may not be seen in all other ca.ses 

 of chemical action. The old body is destroyed, 

 and a new one is formed. The elements for- 

 sake their old combinations and enter into new 

 relations. So when a vessel of chlorine is iu- 

 veited over a warm solution of sal-ammoniac, 

 the explosive chloride of nitrogen is the result, 

 the chlorine and the nitrogen entering into a 

 new relation. Here is a fact which we can ex- 

 plain only by saying that in the peculiar circum- 

 stances mentioned the chlorine and the nitro 

 gen are brought togetlier by chemical affinity, 

 while the sal-ammoniac is decomposed. When 

 the carbonic acid comes into contact with the 

 leaves of plants, similar facts are obsen'ed : the 

 carbon unites with oxygen and hydrogen to 

 form woody fibre, and the carbonic acid is, of 

 course, destroyed. Why should we say that 

 the transformations are due in the fomier case, 

 to chemical affinity, and in the latter to some 

 other agency? What is here saiil of carbonic 

 acid may also be said of water and ammonia. 



But whether we attribute these trausforma- 



