Phosphates and Nitrogen 



or oil of vitriol. In this way the super- 

 phosphate of lime is obtained, which is pro- 

 vided for agriculture by the manufacturer 

 as a most effective manure, especially for 

 cereals. 



Some time ago we were asking what could 

 be contained in the ashes of a burnt plant, 

 and we found potash. Since every plant 

 must have phosphate, if it is to flourish, we 

 must find this in its ashes, since it is in- 

 destructible by heat. After the combustion 

 of any plant, of a truss of hay, or a handful 

 of grain, scientific experiment will always 

 find the combination of phosphorus. It will 

 also be found in the ashes of lime, in the rust 

 of iron, in the silex of pebbles, and many 

 other substances. 



In order to complete this difficult but 

 important subject of the nutrition of plants, 

 something must be said about ammonia. 

 Ammonia is an invisible gas, extremely soluble 

 in water. In combination with other sub- 

 stances ammonia loses its overpowering smell, 

 and forms different compounds, which are 

 among the most effective manures. These 

 compounds provide one of the components 

 of plants, called nitrogen. When isolated, 

 nitrogen is a gas without smell or colour. In 



in 



