BY THE REV. R. F, WHEELER, M.A. 431 



sulphates to be a measure of the sewage in aii*, unless when coal 

 interferes too much to permit allowance to be made.) 



4. — The sulphates rise very high in large towns, because of 

 the amount of sulphur in the coal used as well as decomposition, 



6. — As sulphuretted hydrogen and sulphate of ammonium oxy- 

 dise in the atmosphere, the sulphates may be expected to increase 

 in proportion to the amount of decomposing organic matter con- 

 taining sulphur, such as albuminoid compounds, called conve- 

 niently by a name now less used, protein. 



6. — When the sulphuric acid increases more rapidly than am- 

 monia the rain becomes acid. 



7. — When the rain has so much acid that two or three grains 

 are found in a gallon of the rain water, or forty parts in a mil- 

 lion, there is no hope for vegetation in a climate such as we 

 have in the northern parts of the country. 



8. — The acid is calculated as dry sulphuric, but to some ex- 

 tent the agent may be hydrochloric rendered free by the sul- 

 phuric decomposing the common salt. 



9. — Sulphate of soda increases in the rain as coals are burnt, 

 and if the salts are heated, chloride of ammonium comes off and 

 sulphate of soda remains. 



10. — Chlorides increase with the burning of the coal to a per- 

 ceptible extent, although not so much as in places where salt is 

 decomposed, whether in alkali or other works. 



11. — Free acids are not found with certainty where combus- 

 tion or manufactures are not the cause. 



12. — The chlorides and sulphates may be found neutralized 

 even where there are manufactures. 



13. — By attending to these facts it may be found if the plants 

 in any place are hurt by acid, and by which acid. Other acids 

 may probably be found as readily as the two mentioned. 



14. — By attending to the amount only of the sulphates and 

 chlorides great injustice may be done. The acidity and the 

 average of the district must be known. 



