32 



QUERIES AND ANSWERS. 



Plant 

 Growth. 



!Element. 



Carbon. 



Oxygen. 



Treatment of 

 Manure. 



Manure 

 Odor. 



Horse Dung. 



Nitrogen. 



Sulphuric 

 Acid. 



Pliopphate of 

 Lime. 



Guano. 



TJarnyard 

 Manure. 



165. Q. What are the principal chemicals influencing plant growth ? 

 A. Carbon, oxygen, nitrogen, and hydrogen. 



166. Q. What is an element ? 



A. An element is a body composed of one kind of matter. Carbon, 

 oxygen, hydrogen and nitrogen are elements, but when combined with 

 other substances the new formations are called compounds. 



167. Q. What is carbon ? 



A. It is an element forming a large proportion of vegetable substance. 

 A familiar form of carbon is charcoal. 



168. Q. What is oxygen? 



A. An element known only in a state of gas. It is without taste, 

 smell or color ; it is found in water, air, and in minerals, and is necessary 

 to the continuance both of plant and animal life. 



169. Q. Should manure be kept in piles or heaps? 

 A. Yes, and covered up with soil, as by putrefaction in the open air, five 



per cent, of the nutritive matter will be lost in a month, whereas, if piled 

 and covered, the gases are cooled and absorbed by the external covering. 



170. Q. Why do manure heaps emit a pungent odor? 



A. Because of the gases generated in fermentation, principally sul- 

 phuretted and phosphuretted hydrogen. 



171. Q. Why is horse dung hotter than the excrement from cows? 



A. The excrement of horses fed on grain contains a greater amount of 

 nitrogen and less water than that from other farm animals, consequently 

 it ferments more rapidly 



172. Q. What effect has nitrogen on plants? 



A. It increases the foliage, lengthens the stems of the plants, and pro- 

 longs their growth. 



173. Q. Why is sulphuric acid applied to bones intended for fertilizing? 

 A. Because the phosphate of lime in the bone is the chief manurial 



substance and a larger portion of it is made quickly active as plant food 

 by the application of the sulphuric acid. The resultant of the bones thus 

 treated is afterwards known as superphosphate of lime. 



174. Q. Is phosphate of lime soluble ? 

 A. It is very slowly soluble, especially in dry seasons. Superphosphate 



of lime is extremely soluble. Phosphate of lime continues to exercise a 

 slow but beneficial effect upon fertility, while superphosphate of lime, 

 expending itself in half the period, is a more profitable application. 



175. Q. What is Peruvian guano? 



A. It is the excrement from sea birds, and when good contains lime, 

 potash, Boda, sulphuric acid, phosphoric acid, and nitrogen, the two last 

 named being the most valuable. 



176. Q. Is it true that land never tires of barnyard manure? 



A. Yes, it is ; because stable dung contains all the ingredients and is in 

 a state ready almost for immediate use by growing plants. Sometimes, 

 however, it is advantageous to cease the use of farmyard manure and 



