12 SULPHUR AND THE SULPHATES. 



SULPHUR, SULPHURIC ACID. 



It is now well known that sulphur and its combinations play an important part in the 

 economy of life : hence it is another product to which the farmer must direct his attention. 



No better criterion exists relative to the importance of a product, than that it should be 

 found constantly in the blood and animal tissues. In the case of sulphur, it is always 

 present in albumen and fibrin ; and these are the proximate elements which supply the 

 waste of the body, and by which its growth is promoted and secured. Sulphur, as it exists 

 in albumen, fibrin or casein, is not in an oxidized state, as is proved by the spontaneous 

 decomposition of these substances. When undergoing this change, it is sulphuretted 

 hydrogen which is emitted. 



Sulphur exists in many of the useful vegetables, as peas and beans, and indeed in all 

 leguminous vegetables, both in their juices and mature seeds. In another family of plants, 

 also, sulphur is an essential ingredient, namely, the Cruciferee, as horse-radish, mustard 

 and scurvy-grass. 



Sulphur, as in the case of phosphorus, must be supplied to the soil, by the farmer, 

 whenever it becomes deficient in quantity. That plants invariably derive it from the soil, 

 is proved by the fact that no compound exists in the atmosphere which can furnish it. 

 Sulphuretted hydrogen may sometimes be detected in particular locations, but it is not 

 a substance universally present, or at all adapted in that state to supply the wants of 

 vegetation. 



Sulphur is without doubt derived from the sulphates, of which there are abundant 

 sources in the earth and rocks. Sulphate of lime, or gypsum, is one of the most common 

 sources for supplying this substance to vegetables. The sulphurets of the metals may also 

 furnish it by decomposition. There is, therefore, no want of materials from which sulphur 

 may be obtained. 



Sulphate of ammonia is regarded by Liebig as the substance best adapted for assimilation 

 in the vegetable tissue. This opinion is founded upon the composition of this body. It 

 contains nitrogen ; and as nitrogen is also a constituent of fibrin and albumen, it furnishes 

 both elements by decomposition. The simple removal of the elements of water, hydrogen 

 and oxygen, enables the nitrogen and sulphur to pass over into the composition of the 

 vegetable juices. In the case of gypsum, inasmuch as it is soluble in water, it may also be 

 taken up by the roots of plants, and in their juices undergo decomposition in the presence 

 of carbonate of ammonia. 



The sulphurous, or, as they are usually termed, nitrogenous compounds, albumen and 

 fibrin, are insoluble substances, out of the animal body, or after coagulation by heat. It 

 is supposed that, in plants and animals, their solubility is maintained by the presence of 

 the alkalies. The white of egg furnishes invariably free soda. 



In all the changes and facts respecting the state, condition and growth of vegetables, it 

 is not difficult to see the mutual adaptations of bodies to each other. In the case of sulphur, 



