'.'•.'(I ELEMENTS OF SOILS. 



S inru. This well known substance is widel] disseminated in the mineral kingdom, 



ami is also found Bparinglj in the vegetable and animal kingdoms. The two most cd 1 



combinations are sulphurets and sulphates. In the former condition it is combined with 

 the metals; ia the latter, with oxygen, forming sulphuric acid. In this slate it combines 

 with earths and alkalies, and forms salt*, as sulphate ot lima, of soda, of magnesia, etc. 

 I • an important substance, li is obtained mostlj from Sicily, and is a volcanic product, 

 resulting from the sublimation of a native sulphuret. It may be also procured in this Stale, 

 by the roasting of certain ores iii which it abounds. 



Phosphob.i s. In it* mire state, this is a wluie solid, highly inflammable, comparatively 

 soft and flexible at blood heat, and taking lire readilj bj friction. Ii is quite abundant in 

 the animal kingdom, in combination with oxygen, forming phosphoric acid, which, like 



the sulphuric acid, dunes with lime and other bases, forming salt*. The phosphate of 



lime i* it* most common combination. It is an essential constituent ol bones, and of the 

 coverings of many marine animals, forming in both cases tin- hard substantial part of the 

 animal. It is also met with in the mineral kingdom, li is contained in all good soils, 

 hut only in small quantities when compared with the other elements. It exists in combi- 

 nation with lime, iron ami alumina, ami is detected with difficulty. Both phosphorus and 

 Bulphui form constituent part* ofprott iru . which is regarded a* the ba*i* of albumen, fibi 

 and caseine. 



ro. It i* a constant constituent of the atmosphere. Its origin is not known ; 

 it i*. however, a constant product of combustion and respiration, and in this way continu- 

 ally escapes into the atmosphere. It also escapes from the earth in the neighborhood of 

 volcanoes ; but it is here one of the results of combustion, or of the action of heal on the 

 limestone contained in the interior of the earth. It is heavier than atmospheric air, and, 

 hence, :i operated on by it* specific gravity only, would always be found on the surface of 

 the earth; but gases, when mixed, never behave like liquids, where the heaviest finds 

 the bottom and the lightest the top: they, on the contrary, become equally mixed, and all 

 parts of a volume will he found to contain the same proportion of the heavier and the 



llL r h'' i - B. 



tome acid is a poison. When inhaled, death speedily follow*, unless means are soon 

 instituted for counteracting it* effects. Ii is not Bimpl] a deprivation of oxygen. It extin- 

 guishes a burning taper if immersed in it, or even if it be simply poured over the taper. 

 Hence by trying a suspected gas with a lighted taper, it may be known whether carbonic 

 acid i* present. \\ hen mixed with air in the proportion of 1 to 10, it *nll remains nrespi- 

 rable, producing stupor and death like a narcotic poison. Ii* specific grayitj i*1.52. It 

 - in water, forming an agreeable acid taste. It mm* litmus paper red. 



Carbonic acid 1* liquid under a pressure ol 36 atmospheres = 15 lbs. x 36 on the square 

 inch. If the pressure i* suddenly removed, the evaporation is so rapid that a portion of 

 ile- Liquid solidifies from the lo** ol heat. 



Carbonic acid has a wide ransre of affinity. It is one of the important and most common 

 of ih.- compound elements. This importance is due partly to the ease with which it may 



