TLT.TNOT*; HORTirUI.TURAT, SOCIETY. Ofjf) 



I will now look at the Chemistry of Geology, as we shall need it in 

 the practical management of our soil ; and it will he interesting to know 

 what we are breathing, seeing, and handling. 



There are known to chemists only sixty simple bodies, or elements 

 in nature. Forty-four belong to the class of metals; sixteen are con- 

 sidered non-metallic, and ov\y fourteen of them enter tnto the rocks nnd 

 soils to constitute the greater part of the earth, its waters, and .ttrnnsphere. 



r will take them in the order of their abundance. 



1. Oxygen — A transparent colorless gas. The inost powerful 

 and almost universal supporter of combustion. Not only carbon in all 

 its forms burns brilliantly in it, but iron and steel burn as bright as the 

 sun ; and adding one part of hydrogen gas to eight parts of oxygen and 

 placing marble or chalk at the place of union, they will burn too brilliant- 

 ly to look upon. 



It is the universal supporter of life in breathing, but if pure, we 

 should live too fast and soon die. It makes up more than one-fifth 

 of our atmosphere and eight-ninths of water — river, lakes, seas, and 

 oceans, — and forms two-fifths of the earth's crust. It has the greatest 

 range of affinities of all known substances. 



2. Silicon — A dark, nut-brown powder, equivalent, 22. t8; 

 with oxygen Silica and equals three-fifths of the crust of the earth and 

 comes under the names: silica, silicic acid, silex, and silicates, quartz, 

 flint, sand, agates, etc., etc. 



3. Calcium — A yellowish white metal, and of no account till twenty- 

 fi\e parts of it unite with eight parts oxygen and forms Protoxide of 

 Calcium or quick-lime. Quick-lime has a strong attraction for carbo- 

 nic acid, and with it forms Carbonate of l.ime. 



One-seventh of the earth's crust, under the names of marble, lime- 

 stone, chalk, rhomb-spar, etc., abundant and useful. 



Carb. of lime or quick-lime, with sulphuric acid forms (iypsum or 

 Plaster of Paris, useful both in the soils and arts. 



4. Aluminum — Equiv. 1^.7. Is a gray powder, with a metallic lus- 

 ter, and burns in oxygen gas, or when heated in ( onmion air, with a 

 bright light, forming Alumina^ Kquiv. Al. 2. O 3. 



t'ure Alumina is a tine white powder, smooth to the touch, and is 

 the basis of all our earthen-ware and pottery. Mixed with sand it forms 

 our clays, and is supposed to form one-sixth part of the soils of New 

 England. yV very abundant production in nature, in every region of the 

 globe, and in rucks ol all ages. Slates and sh.iles are specimens. The 

 oriental ruby and sa])i)hire, an- pure Ahimin.i, and Si)in(l .-md other 

 gems, with emery, are nearly so. 



Alumina closes up the open pores in the st)ils and makes resting 

 places for plant food, called also geine, and sometimes by a half dozen 

 other names, as : extract of humus, carboniferous mould, humin, crcnic 

 and apocrenic acid, etc. 



The Alum of the market is a sulphate of alumina, sulphate of po- 

 tassa, and water. 



15 



