68 IOWA ACADEMY OF SCIENCES. 



million. The solids are composed largely of common sub- 

 stances such as sodium chloride, sodium sulphate and 

 magnesium sulphate. The mineral analyses of many of 

 the samples have been published recently and it is unnec- 

 essary to give consideration to this matter here.f 



The amount of solids in the deep well waters has had a 

 tendency to cause them to be looked upon with suspicion. 

 When the solids on evaporation in the deep well waters 

 are compared with those of some of the noted mineral 

 springs * as for example. 



Solids on evaporation 

 in parts per million. 



PfaEfers 252 



Toplitz 295 



Spa 563 



Teplitz 626 



Ems 2,781 



Carlsbad 5,455 



Wiesbaden 8 , 262 



Seidlitz 16,406 



Saidschutz 23,285 



Pullna 32,771 



It is readily seen that while none of the samples have 

 solids as high as the springs having large amounts of min- 

 eral substances yet they will compare favorably with many 

 given in the above table. Many of the samples of water 

 have been tested for lithium with the spectroscope and the 

 results obtained showed that this substance was present in 

 all of the samples that have been tested. 



The deep well waters may be said to be characterized by 

 the fact that they contain only traces of nitrogen as 

 nitrites and nitrates. In the Centerville sample the nitro- 

 gen as nitrates was caused by the sample standing for some 

 time and as a result the free ammonia was oxidized by the 

 nitrousfying process to nitrous acid. This feature of the 

 deep well waters in which the free ammonia is changed 

 to nitrites and nitrates has been observed in many samples 

 of water and it is hoped that the changes can be investi- 

 gated in the near future. The oxygen consumed as has 



+Iowa Geological Survey. Vol. 6. Artesian Well Waters. 

 •Smith. Foods, p. 310. 



