98 Wood's Class Book of Botany. [August, 



ammonia is produced from the nitrogen of the atmosphere; and, 

 finally, apocrenate of ammonia, carbonic acid and water." 



This long extract seemed to be required in order to put the 

 reader in possession of the views of Mulder on this important 

 subject; from which it is well established that organic matter in 

 soil is of the highest moment; and that it not only ministers 

 indirectly to the growth of plants, as stated in the early part of 

 this article, but also becomes food itself in the form of apocrenate 

 of ammonia. So, also, that important substance, carbonic acid, 

 is liberated and furnished to the roots; a substance which many 

 suppose is taken up by the leaves only. The apocrenates are 

 continually forming; not only the apocrenate of ammonia but 

 also those of potash, lime and magnesia. 



Through, then, the action of the organic acids the inorganic 

 bodies are received also into the circulation of vegetables; and 

 this gives us an idea of its importance, namely, as a medium 

 by which lime, magnesia and potash are supplied to the vegetable 

 kingdom. The carbonates of lime and magnesia are rather in- 

 solulale bodies, though the carbonates of soda and potash are, as 

 is well known, highly soluble. 



We should take an unsafe course in practice, then, in rejecting 

 the organic part of manures; and how truly important lime, 

 potash, soda, magnesia, &c., they are; still, soil cannot and is not 

 fertile if they contain only these; and the highest and most valua- 

 ble soils are those in which a due balance is preserved between 

 the organic and the inorganic part. 



WOOD'S CLASS BOOK OF BOTANY. 



The second edition of this popular and interesting work has 

 just been published. The character of the first edition was early 

 announced in this journal. It contained one of the greatest im- 

 provements in the study of modern botany. Adopting the 7)otU" 

 ral system, it employed the Linntean method as a mere index to 

 lead to the natural orders, or genera of plants. It was the hap- 

 piest application of the artificial method that had ever been made, 

 and comported exactly with the great end designed by the im- 

 mortal Linnaeus himself. He failed to perfect the natural method 

 he had begun, because he could not attain the requisite knowledge 

 of plants, and because the structure of vegetables had been so little 

 examined. Owing to the splendor of his attainments and the ad- 

 mirable simplicity of his artificial system, as well as the devoted 



