142 Review of Essays on Calcareous Manures. 



were originally barren hills of blowing sand. They now yield a great- 

 er product than any other part of Europe. Great industry and la- 

 bor have no doubt been expended in obtaining and applying putres- 

 cent manures, and in this region the clover husbandry had its rise ; 

 but with all this, no permanent fertility could have been given with- 

 out the use of lime, and those substances which contain its com- 

 pounds. At present alight friable mould of greater depth than can 

 be reached by the plough, and which is therefore occasionally trench- 

 ed by the spade, covers the whole of the ancient dunes, and the whole 

 country presents an aspect, of which no part of ours can even furnish 

 an idea, with the exception of the garden grounds of the ShaJcers at 

 Lebanon. 



We fully concur with the opinion of M. Puvis in respect to the 

 importance of earthy and saline matter, not only as forming a basis of 

 proper character to support the plant, but as itself forming an essential 

 part of the food. We on the other hand cannot but express our dis- 

 sent from the opinion, which derives the other elements necessary to 

 growth of plants wholly from the atmosphere. If he mean indirect- 

 ly, through the intervention of the soil, he is to a certain extent 

 right, for most of the water which is the vehicle of all their nutriment, 

 yields at least one of their essential elements, and is itself incorpora- 

 ted with the plants, is derived from the atmosphere in the shape of 

 rain and dew. But the gases it dissolves and carries with it, and 

 which yield the carbon and part of the hydrogen of plants, are all de- 

 rived from the decomposition of organic matter in the soil itself. 

 When therefore we can find, in the absorption of water by the roots ; 

 its ascent in the form of sap ; its elaboration in the leaves, where so far 

 from an absorption from the atmosphere taking place, oxygen is 

 evolved ; in the subsequent descent of the altered sap in the form of 

 gum, resin, &£c. a sufficient reason for the supply of the parts M. Puvis 

 seeks in the atmosphere : we are compelled to dissent from his con- 

 clusion. There is one curious fact in connexion with this subject, 

 that we have never seen mentioned. It is obvious that while lands 

 still retain a large quantity of vegetable matter, arising as it may, 

 from their having been for ages in the state of forest, little benefit is 

 to be hoped from putrescent manures, while there may be earthy 

 substances essential to the growth of particular plants, which the soil 

 does not contain. In such a case earthy manures are likely to be 

 extremely serviceable. 



