APPENDIX. 211 



the power which it possesses, of absorbing water with rapidity, 

 and, after its saturation, of allowing all other water to sink 

 through it, are causes also of its favourable effects. These 

 experiments show what a close affinity the component parts 

 of charcoal have to all plants, for every experiment was 

 crowned with success, although plants belonging to a great 

 many different families were subjected to trial/' (Buchner's 

 Repertorium,\\. Reihe, xix. Ed. S. 38.) 



ON THE ROTATION OF CROPS AT BINGEN ON THE RHINE. 

 (See Page 172.) 



The alternation of crops with esparsette and lucern is now 

 universally adopted in Bingen and its vicinity as well as in 

 the Palatinate ; the fields in these districts receive manure 

 only once every nine years. In the first year after the 

 land has been manured, turnips are sown upon it, in the next 

 following years barley, with esparsette or lucern ; in the 

 seventh year potatoes, in the eighth wheat, in the ninth 

 barley ; on the tenth year it is manured, and then the same 

 rotation again takes place. 



ON A MODE OF MANURING VINES. 



The observations contained in the following pages should 

 be extensively known, because they furnish a remarkable 

 proof of the principles which have been stated in the preced- 

 ing part of the work, both as to the manner in which manure 

 acts, and on the origin of the carbon and nitrogen of plants. 



They prove that a vineyard may be retained in fertility 

 without the application of animal matters, when the leaves 

 and branches pruned from the vines are cut into small 

 pieces and used as manure. According to the first of the 

 following statements, both of which merit complete con- 

 fidence, the perfect fruitfulness of a vineyard has been 



P 2 



