DISSOLVED CONTENT OF WATER. 



903 



the extreme faults of the water in the well with respect to both oxygen and 

 nitrogen. 



In addition to the troughs, tin pans with perforated bottoms were used to 

 correct the water. Usually the water was passed through a series of 6, arranged 

 one above the other, with a fall of 4 inches from one bottom to the next. The 

 pans were rectangular, about 31 by 19.6 by 5 centimeters, and contained 345 

 circular holes i millimeter in diameter, regularly placed, punched from the 

 inside with a steel punch. In table iii the results with these pans may be 

 compared with those from the troughs , on 2 , 4 , and 6 liter flow . The " untreated ' ' 

 samples were taken directly from the delivery pipe before appreciable contact 

 with air. In comparing the results, or when considering in any case the amount 

 of air or any gas dissolved in water, the temperature of the water must always 

 be borne in mind, the colder water holding or being capable of holding more gas 

 dissolved than warmer water. 



Table III. — Well Water from Hydraulic Pump, Untreated, after Passing through Sanded 

 AND Pebbled Troughs, and after Passing through Six Perforated Pans. 



Sample. 



Untreated 



Do 



Do 



Through troughs. 



Do 



Do 



Through 6 pans_. 



Do 



Do 



Untreated 



Do 



May 14, 3 p. m 



May 14, 4 p. tn 



May 15, 9.30 a. m_ 

 do 



May 15, 5 p. in.__ 

 May 16 



May 15, 3 p. m.__ 



May 16, 4 p. m 



May 16, 12 noon _. 



May 16, 9 a. m 



May 16, 1.30 p. m- 



Flow per 

 minute. 



Liters. 



Temperature of 

 water. 



Entering 

 troughs. 



"C. 



Leaving 

 troughs. 



"C. 



C02. 



16. 9 

 16.8 

 21. o 

 13-2 

 13-7 

 15- I 

 13-3 

 14. o 

 14.8 

 23.0 

 22.5 



4.6 



3-7 

 2.6 

 5-6 

 5-2 

 5- I 

 5-8 

 5-3 

 5-4 

 I. I 

 I. 2 



Several facts of interest appear from the trials of the pans and troughs. In 

 the first place, neither succeeds in completely correcting the water with respect 

 to either gas. After passing either system the water could, by further exposure, 

 take up a little more oxygen and release more nitrogen. With the 2-liter 

 flow, however, the correction is very nearly complete for oxygen, but it 

 must be remembered that the hydraulic pump had already added some oxygen. 

 The correction is less complete by both troughs and pans as the flow grows 



