154 Diffusion of Agricultural Knowledge. [March, 



41. Finally. The necessity for so extensive an atmosphere as 

 surrounds the earth, is obvious. It must be so constituted that the 

 relative proportions of its oxygen, nitrogen, vapor of water, car- 

 bonic acid, and ammonia, shall be so nearly preserved as is suited 

 to the conditions of the vegetable and animal kingdoms. Too 

 great an excess of carbonic acid and ammonia, would endanger 

 the race of animals, as would also a great excess or deficiency of 

 oxygen. But in some times and places, a vastly greater amount 

 of carbonic acid is poured into the atmosphere, and the oxygen is 

 made to disappear to the same extent. Animal life would in such 

 places be exposed to destruction, from the abstracting of oxygen 

 and the abounding of carbonic acid. With all the facility with 

 which the gases diffuse themselves among each other, were the 

 atmosphere of very limited (extent, danger and death would be at 

 hand. But with the great extent of the atmosphere, and the dif- 

 fusiveness of gases and vapors, there is no such possibility. Now 

 the adaptation of the three kingdoms to each other, prevents this 

 result. The heated and cooled air, the moist and the dry, the land 

 and the sea air, the tropical and the polar air, abounding in oxy- 

 gen or carbonic acid and ammonia, or the contrary, the air at the 

 surface of the earth and high in the atmosphere, aided by the wa- 

 ter which absorbs the carbonic acid and ammonia, and brings 

 them to the earth, are all so mingled and diffused in their due 

 proportions, that the animal and vegetable worlds are secure and 

 flourishing, and " nature is dressed in smiles." The adaptation 

 is beautfiul, admirable, wonderful. In wisdom hast THOU made 

 them all. 



THE DIFFUSION OF AGRICULTURAL KNOWLEDGE 

 IN MISCELLANEOUS JOURNALS. 



It is with pleasure that we see some of our exchange papers 

 that are not professedly devoted to the interest of farming, pub- 

 lishing in their columns scientific essays upon that subject. The 

 Philadelphia Saturday Courier has published a sei-ies of these ar- 

 ticles both useful and interesting to the lover of agricultural 

 knowledge. The writers appear to aim at elementary truths in 

 treating of those productions that are brought forth and fostered 

 by the aid of human labor. Such articles cannot be too highly 

 prized in this age of the world when reading is so universal among 

 civilized nations. At no period in the history of man has there 

 been so vast an amount of publications issued from the press as 

 at the present time. Every book establishment in the land is 

 filled with them, every mail is burthcned with their weight and 



