76 ttORTH-CAROLINA GEOLOGICAL SURVEY. 



tilizing matter applied to the best advantage, I have carefully 

 determined the composition of its ash from specimens which 

 I obtained in Wake county. 



The percentage of ash of the pea vine, destitute of leaves 

 and in the condition in which it is fed to cattle, and as derived 

 from 268 grains of the stems and branches in a perfectly dry 

 state, I found to be 4.570. 



On submitting this ash to analysis I found it composed of 



Potash, . 7.800 



Soda, 5.650 



Earthy phosphates, 19.800 



Lime, 16.400 



Magnesia, 30.040 



Sulphuric acid, 11.710 



Chlorine, 1.710 



Silica, , 10.900 



Soluble silica, 6.000 



When we find so large a percentage of ash, and a compo 

 sition clearly rich in inorganic constituents, we may not doubt 

 the utility of employing this plant as a fertilizer instead of 

 the clover plant, as it is considerably richer in the expensive 

 elements of nutrition. 



50. The pea with its pod is richer in phosphates than the 

 vine, and as these are ripe when turned under the value of 

 the crop for this purpose is increased. 



The percentage of ash, as determined from 365 grains of 

 the dried pod with the pea, is 3.13. The percentage of ash 

 is greater from the presence of the pod. But this being 

 ploughed in the result is more accurate from their combina 

 tion. If the nutrient matters of the pea were to be deter 

 mined it should be analyzed by itself. 



The composition of the pea, with its pod, I found as follows : 



Potash, ... 24.200 



Soda, 10.7^9 



Earthy and aikaline phosphates, 32.200 



Carbonate lime, 11 000 



Magnesia, 3.000 



