TUB AGRICULTURAL JOURNAL. 



621 



oxides, or anhi/drides, given to them. 

 They are chiefly the oxides of non-metals. 

 Most of the oxides of the metals, 

 en the other hand, do not cause 

 the formation of acids, but if they are 

 brought into contact with acids fhey pro- 

 duce salts, identically the same as those 

 formed from the metals theuiselves. In 

 this case, however, no hydrogen is set 

 free, but it combines with the oxygen of 

 the oxide instead, forming water. This 

 will perhaps be clearer if we illustrate 

 the reaction which occurs when iron 

 oxide acts upon sulphuric acid with the 

 consequent formation of sulphate of iron. 

 Before re-action we have — 



Sulphuric acid and Iron oxide 



hydrogen ] 

 suljjhur > and 

 oxygen ) 



After reaction we get 



Iron xulpliate and 



iron j 

 sulphur > and 

 oxygen ) ' 



Oxides of this kind are called basic 

 oxides or bases. When so brought into 

 contact with acids thejf neutralise them ; 

 that is, prevent them having any action 



iron 

 oxygen. 



Water 



hydrogen 

 oxygen. 



on litmus paper, which is the usual test 

 for the presence of an acid. This is ex- 

 pressed by saying that most salts are 

 neutral to litmus ; this rule, however, has 

 a good many exceptions. 



Below are a few simple questions on 

 the foregoing, to enable anyone to test his 

 grasp of the subject so far. 



1. The ancients used to call earth, air, 

 fire, and water the four elements. Were 

 they right in so doing ? 



2. What are the chemical names of 

 water, lime, spirits of salt, iron rust ? 



3. What weight of oxygen is contained 

 In ;^61bs. of water ? How much in 10 

 cubic feet of air ? 



4. Explain exactly the connection be- 

 tween an acid and a salt. 



5. If calcium oxide were acted on by 

 sulphuric acid, what substances would 

 you expect to be formed ? 



6. Mention two other names by which 

 hydrochloric acid is known. 



7. What is meant by a sulphate ? 



8. Why is hydrogen sometimes used to 

 fill balloons ? If you were asked to make 

 some, how would you proceed ? 



9. How would you try and find out 

 whether a certain soil was acid or not ? 



(7o be continued.) 



By Morris 



AS this matter is ever with us, a few 

 remarks on what is known as district 

 responpibility, as a means of preventing 

 the crime, may not be out of place. At 

 the outset we may at once admit that 

 sheep-stealing is one of the most difficult 

 tilings to stop, and even in England, until 

 recent times, the punislunent on convic- 

 tion was death, showing that even in a 

 closely settled country severe measures 

 were needed. District respousibililj' has 

 long been advocated by sheep-fanners 

 who were at their wits end for a means of 

 preventing this crime, and now that it is 

 the law of the land I propose to say a few 

 words as to the steps necessary to get it 

 put in force. 



A. Sutton. 



The first thing the sheep-farmer must 

 see to is that he keeps a proper list of 

 sheep or other stt>ck, and a true record 

 must be kept of actual counting of such 

 stock, made at intervals of not less than 

 one month ; all deaths or sales must be 

 duly entered. This will commend itself 

 to all careful farmers, and it is obvious 

 that some such course is absolutely neces- 

 sary in order to show conclusively that 

 due care has been taken and reasonable 

 attention paid. 



When sheep are being stolen, and th>i 

 owner can find no trace or evidence in 

 the matter, it is first necessary to give a 

 written notice either to the Resident 

 Magistrate of the Division or to the police 



