252 CATECHISM OF 



purchase plaster largely or not ? 409. Will you give the several 

 efifects which plaster produces on soils adapted to it ? 410. 



Will plaster operate well alone permanently ? 411. What does 

 it require? 411. In what two ways is organic matter added 

 when plaster is used on pastures? 411. How should it be added 

 when plaster is used on mow-lands? 411. How on ploughing ? 

 411. Should we complain of plaster because other manuring is 

 required to keep the land permanently good? 411. What of 

 ashes? 411 and 56, near the end. 



Does the subject of capillary attraction, as explained in 387 and 

 onward, throw any light on the question of deep ploughing? 413. 

 In what case might it be bad policy to plough deeply ? 413. If 

 the soil is deep, and the subsoil compact, what do you say ? 414. 

 Eeasons ? 414. 



On all ordinary soils, how deep should we plough at least ? 415. 

 If the soil below that depth is impervious to water, what should 

 be done ? 415. What two dangers do you thus escape ? 415. 

 What positive benefit do you gain ? 415. 



Explain the operation of water as a carrier of food to plants ? 

 416. Will you illustrate still more fully the necessity of the free 

 passage of water and air through the soil? 417. 



What is said of the importance of deep ploughing? 418. What 

 caution is to be observed? 418. What would be the safest 

 course? 419. 



What is said of mixing unlike soils? 420. How may this 

 sometimes be done without the labor of transportation? 420. 

 What cause sometimes prevents the good eflfect of deep plough- 

 ing ? 420. 



How may the farmer judge whether his land is troubled with 

 the protoxide of iron ? 420. If it should prove to be so, what 

 may he do ? 



How many oxides of iron are there in soils? 53 and 54. 

 Which of these is very soluble in water ? 53. What is its effect 

 on plants ? 53. To what does this oxide turn when exposed to 

 the sun and air ? 53. 



What is said of a properly prepared soil? 421. How does it 

 sustaiji vegetation ? 421. What auxiharies has it ? 421. What 

 further is said of such a soil ? 422. 



What is said of the best time for cutting grass ? 423. Of the 

 importance of early hoeing ? 423. Of the time when wheat, rye 

 and oats should be cut? 423. Which gives most hay, early or 

 late cutting? 423. Which gives the best ? 423. 



What frequently occupies the attention of farmers after hay- 

 ing? 424. Which of those great improvements, before spoken 

 of, would he be tempted to enter upon first ? 424. Why may 

 we suppose that he will prefer to take hold of the business of 

 draining? 424. 



What sort of a s\\;amp is it, livhich he wishes to drain ? 424 



