1847.] Coal Ml as a Manure. 289 



COAL ASH— ITS NATURE AND PROBABLE VALUE 

 AS A MANURE. 



The question has no doubt often arisen whether the ancient 

 vegetation was analagous in its inorganic matter to that of the 

 present day. Reasoning from those facts which we are sure of, 

 very few doubts can remain as it regards the position that plants 

 w^ere constituted as they are now, that the same elements entered 

 into their composition. The soil being derived from the same 

 rocks as now, and the same forces which gave them birth, and 

 which also sustained them, go to prove the validity of the assump- 

 tion. 



But a question will arise on reflection, that admitting this po- 

 sition, do the preserved plants still retain the elements which 

 nourished them when living. Have they not been dissolved out 

 under the vicissitudes to which they have been exposed, and that 

 some other substances have been substituted in their place. This 

 question can be only answered by analysis of the ash which is 

 left in the combustion of the coal, though the idea would probably 

 be entertained without resorting to this process, that very likely 

 the most soluble, such as potash and soda, would disappear. 

 Having been engaged for some time in the analysis of the ash of 

 the different vegetables, these several questions came up for solu- 

 tion, and accordingly a few analyses were made. The following 

 result will express generally the composition of coal ashes. 



Analysis of the JJsh of the Peach Mountain Coal. — Color Grey. 



Silex and silicates, 79.34 



Sulphuric acid, ........ 1.50 



Chlorine, .06 



Carbonate of lime, 8.36 



Phosphate of lime, and phosphate of per oxide of iron, . 4.50 



C. magnesia, 1.84 



Alumina and per oxide of iron, 2.00 



97.50 

 It appears from the above analysis that we may suspect the pre- 

 sence of the phosphate of lime in coal ashes, and hence practically 

 that they are important in agriculture, even though w^e omit to 

 notice the carbonate of lime and magnesia which they contain. 

 The alkalies were not sought for. Leaving their value in agricul- 

 ture out of account, this and other analyses seem to prove that 

 the ash is truly in a great measure the ash of coal plants. If so, 

 we may infer that the composition of plants of the coal period 

 was not greatly dissimilar to that of the plants of the present day. 



