VEGETABLE MOULD. 315 



counting for the origin and formation of diamonds, 

 except the process of decay. Diamonds cannot be 

 produced by the action of fire, for a high tempera- 

 ture, and the presence of oxygen gas, would call 

 into play their combustibility. But there is the 

 greatest reason to believe that they are formed in 

 the humid way, that is, in a liquid, and the process 

 of decay is the only cause to which then* formation 

 can with probability be ascribed. 



Amber, fossil resin, and the acids in mellite, are 

 the products of vegetable matter which has suffered 

 decomposition. They are found in wood or brown 

 coal, and have evidently proceeded from the de- 

 composition of substances which were contained 

 in quite a different form in the living plants. They 

 are all distinguished by the proportionally small 

 quantity of hydrogen which they contain. The 

 acid from the mellite (mellitic acid) contains pre- 

 cisely the same proportions of carbon and oxygen 

 as that from amber (succinic acid) ; they differ only 

 in the proportion of their hydrogen. M. Bromeis* 

 found that succinic acid might be artificially formed 

 by the action of nitric acid on stearic acid, a true 

 process of eremacausis ; the experiment was made 

 in this laboratory (Giesseri). 



VEGETABLE MOULD. 



The term vegetable mould, in its general sig- 

 nification, is applied to a mixture of disintegrated 



* Liebig's Annalen, Band xxxiv., heft 3. 



