26 VETERINARY HYGIENE 



The top of the well should be raised 6 to 12 inches above the ground 

 and covered with a proper flagstone or iron cover. 



Farm wells are very liable to pollution, especially after heavy 

 rain, from the washings of cattle-courts, &c., the drainage of which 

 is usually unsatisfactory. When making an examination of a well 

 very careful attention should be paid to its construction and state 

 of repair. The position of all drains in the vicinity, both surface 

 and sub-soil, should be noted, and also the position of cesspools, 

 sheep-dipping tanks, manure pits and the like. The carcases of 

 animals are sometimes buried without due consideration being given 

 to the possibility of subsequent pollution of the water draining into 

 wells. Should a buried carcase be found to be the cause of contami- 

 nation it is necessary to remember that permission to exhume 

 and remove it has to be obtained from the Ministry of Agriculture 

 and Fisheries, see Animals (Transit and General) Order, 1912, 

 and Horses (Importation and Transit) Order, 1913. The extent 

 of the ground surrounding a well that should be examined depends 

 chiefly on the nature of the sub-soil, and on the depth of the well. 



The Collection of Samples. Many veterinary surgeons are 

 called upon from time to time to collect samples of water for 

 analysis. An improperly taken sample is useless, and may give 

 quite erroneous results when subjected to analysis. 



As the examination of a water supply is often done when a claim 

 for alleged damage is contemplated, the greatest care is necessary 

 when taking the sample to see that there is no extraneous contami- 

 nation or other possible source of error. 



The following directions are, in the main, abstracted by permis- 

 sion from Dr. Thresh's Examination of Waters and Water Supplies. 

 The water should be collected in white glass bottles having well-fitted 

 glass stoppers. A Winchester quart, holding about half a gallon, 

 is convenient and easily obtained. Dark coloured bottles are 

 to be avoided. When possible, bottles should be obtained from the 

 laboratory making the test, as they are sent out chemically clean 

 and all that is necessary is to remove the stopper and fill the bottle 

 with the water. If bottles are not supplied by the chemist, care 

 should be taken to choose clean ones, which should be well washed 

 out, rinsed with acid, and then washed repeatedly with clean water. 

 The stoppers must be cleaned in the same manner and then placed in 

 the bottles. When filling a bottle with the water to be tested the 

 stopper should be held in the hand and not laid on the ground. 

 The bottle should be filled with the water and emptied three or 

 four times. At the final filling a space should be left at the top, 

 otherwise, if the bottle is quite filled, the neck is liable to crack 



