WATEE 



27 



The pollution of the well-water is due to sewage, as indi- 

 cated by the nitrogen, free ammonia, and chlorine (Parkes). 

 In the table it will be observed that nitrates and nitrites 

 are absent from sewage. They are only found when a 

 certain amount of oxidation of organic matters has occurred, 

 hence their presence in polluted well and river water. 



QUANTITY OF WATEE EEQUIKED. 



The quantity of water required has been made the subject 

 of many experiments. It is obvious that the amount is in- 

 fluenced by the time of year, and in the case of horses by 

 the work performed. Further there are certain operations 

 of the stable, flushing drains, washing carriages, etc., which 

 are all included in the calculated daily supply per head. 



Stating the amount in round numbers required by horses 

 for drinking purposes alone, it may be placed at between 

 7 and 8 gallons daily. Eather less perhaps in the winter, 

 rather more in the summer. The largest amount of water 

 is generally drunk at noon, but again this depends upon 

 the work the horse is performing. 



The amount required for stable cleansing and other 

 operations is about equal to the amount consumed ; so that 

 experience indicates 16 gallons of water per head per diem 

 as the probable amount required. 



Observations made on board a ship during the Abyssinian 

 Expedition furnish the amount of water required by other 

 animals for drinking purposes :— ^ „ , ., 



Gallons daily. 



Elephants •■- -■- •■• ••■ ^5 



Camels 



Draught bullocks 



Pack buUooks 



Horses 



Mules and ponies 



The quantity of water required daily in hospitals for sick 

 animals is difficult to determine, and must depend upon the 

 type of case. Surgical cases cause a very heavy drain on 

 the water supply, especially if irrigation of wounds or 

 sprains be practised. 



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