64 



NEW ENGLAND FARMER. 



March 



CATECHISM 



— OF — 



AGRICULTURAL CHEMISTRY AND GEOLOGY. 



BY JAME3 P. W. JOHNSTON, M. A. 

 fCONTINDED.] 



Q. Woody fibre, starch, gum, and sugar consist 

 of carbon and water only ; of what does toater it- 

 self coiisist ? 



A. Water consists of oxygen and hydrogen. 



Q. Hoio much of cadi of these elements is con- 

 tained in u'ater ? 



A. Every 9 lbs. of water contain about 8 lbs. 

 of oxygen, and 1 lb. of hydrogen. 



Q. Is it not a very extraordinary thing that 

 liquid water, tchich pids ovt all fircf shoidd consist 

 of two gases, cme of tvhich (hydrogen) burns read- 

 ily, tviiile in the other (oxygen) bodies burn with 

 great brilliancy ? 



A. Yes, it is very wonderful ; but there are 

 many other substances the composition of which 

 is almost equally extraordinary. 



Q. Can you name any such substances ? 



A. Yes, it is almost equally extraordinary that 

 v)hite starch should consist of black charcoal and 

 water only, — and that sugar and gum should con- 

 sist of the same elements as starch and woody 

 fibre. 



Q,. Of ichat elements, then, do these substances 

 cojisist ? 



A. They all consist of carbon, hydrogen and 

 oxygen. 



Q. Of ivhat does gluten consist ? 



A. Gluten consists of all the four elements — 

 carbon, hydrogen, oxygen and nitrogen — united 

 together. 



Q,. Does the plant derive from the air all the el- 

 ements of tchich gluten consists 7 



A. No, it may obtain carbon, hydrogen and 

 oxygen, as we have seen, from the air, but the 

 nitrogen it obtains almost solely from the soil. 



rv. — Of the Soil on which Plants Grow. 



Q. What does the soil consist of? 



A. The soil consists of an organic or combus- 

 tible, and of an inorganic or incombustible part. 



Q. IIoio do yoti show this 7 



A. By heating a portion of soil to redness on 

 a bit of sheet iron, or on the end of a knife, 

 either in the fire or over a lamp. The soil will 

 first turn black, showing the presence of carbona- 

 ceous matter, and will afterwards assume a grey 

 brown or reddish color as this black organic mat- 

 ter burns away. 



Q. Whence is the organic part of the soil de- 

 rived ? 



A. It is derived from the roots and stems of 

 decayed plants, and from the dung and remains 

 of animals and insects of^various kinds. 



Q. Does this organic part form a large propor- 

 tion of the soil ? 



A. Of peaty soils it fcms sometimes three- 

 fourthe of the whole weight; but of rich and fer- 

 tile soils it does not usually form more than from 

 a twentieth to a tenth of the whole weight. 



Q. Can a soil bear good crops which does not 

 contain a considerable 'proportion of organic mat- 

 ttrf 



A. Not in our climate. A rich soil generally 

 contains at least one-twentieth of its weight (<5 



per «ont A of rvvcTanip r^nttpr. 



Q. Does the organic matter increase or dimin- 

 ish in the soil, according to the way in which it is 

 cultivated ? 



A. Yes, it diminishes when the land is fre- 

 quently plowed and cropped, or badly manured 5 

 and it increases when the land is planted, when 

 it is laid down to permanent pasture, or when 

 large doses of farm-yard manure or of peat com- 

 post are given to it. 



Q. What purpose does this organic matter serve 

 in the soil"} 



A. It supplies the organic food which plants 

 draw from the soil through their roots. 



Q. Do p)lants draw nrnch of their organic food 

 from the soil ? 



A. The quantiy they draw from the soil varies 

 with the kind of plant, with the kind of soil, and 

 with the season ; but it is always considerable, 

 and is necessary to the healthy growth of the 

 plant. 



Q. If plants ahoays draw this organic matter 

 from the soi^-, tvill the soil not become gradually 

 p)Oorer and less productive^ 



A. It will, if badly managed and constantly 

 cropped. 



Q. Then Jiotv can you keej) up the supjily ? 



A. By plowing in green crops, — by growing 

 clovers and other plants which leave long roots in 

 the soils, — by restoring all the hay and straw to 

 the land in the form of manure, — or by laying 

 down to pasture. 



Q. Whence is the inorganic paH of the soil de- 

 rived ? 



A. The inorganic part of the soil is derived 

 from the crumbling of the solid rocks. 



Q. Of what do these rocks principally co7isist? 



A. 1 hey consist of more or less hardened 

 sandstones, limestones and clays. 



Q. Do soils consist primipally of the same sub- 

 stances ? 



A. Yes, soils consist principally of sand, clay 

 and lime. 



Q. How would you name a soil ichich contained 

 one of these substances in large quantity ? 



A. If it contained very much sand, I would 

 cf.ll it a sandy soil ; if much clay, a more or less 

 stiff clay soil ; if much lime, a calcareous soil. 



Q. But if the soil contained two or WMre of 

 them in large proportions how ico^dd you name it ? 



A. A n)ixiure of sand and clay with a li tie 

 lime, I would cull a loam; if much lime was pres- 

 ent, I would call it a calcareous loam ; and if it 

 were a clay with much lime, I would call it a cal- 

 careous clay. 



A Useful Hint to House-Keepers. — A gen- 

 tleman who has tried the plan successfully for 

 five years, communicates the annexed method of 

 preventing horses from chafing under tlie c liar. 

 He says 1)e gets a piece of leather, and has what 

 he terms a false collar made, which is simply a 

 piece of leather cut in such a shape as to lie 

 snugly between the shoulders of the horse and the 

 collar. This feeds off ail the friction, as the col- 

 lar slips and moves on the leather, and not on the 

 shoulders of the horse. Chafing is caused by the 

 friction, hence you see the thing is entirely plausi- 

 ble. Some put pads or sheepskins under the col- 

 lar, but these do as much harm as good, for ihey 

 augment the heat. A single piece of leather, like 



