S4 TOWA ACADEMY OF SCFENCES. 



report b}' Prof. C. D. A\'h}tnev contains many analyses of 

 vo'ks and minerals. In the s<Hond survey the re])ort on 

 chemistry, from Prof. Kush Emery shows a irreat amount of 

 work upon the rocks, muierals, waters and coal of the State. 



As^ide fr(mi this, however^ no little work has been done in 

 the way of analyses of water fiom the various streams and 

 other water s^upplies of the State, hir<>-el\' throuo'h the efforts- 

 of the State Board of Healtli. Messrs. Pope, lii)l)l)ins,. 

 Shearer, l>ennett, Andrews, II -n-ick and others have done 

 much in this line, and v/hile in many cases these analyses 

 hive not been puhlislied in any fvn-m acce,s-;il>h> to the scien- 

 titic world, I believe that a careful collection and comparative 

 statement of all that could be hrouoht tosrether would fur- 

 nish an exceedino-ly valuable and interestinu' document. 



Aside from the economic question of water su[)ply for cities 

 and towns, and omitting- the question of mcn-e organic contam- 

 ination, such analyses must furnish a hint, at least, as to the 

 mineral constituents of the soils from which the water is col- 

 lected, and especially in the case of mineral springs or arte- 

 sian wells some information as to the character of the deeper 

 geological deposits, of their respective areas. 



Chemical analyses upon rocks, coals, fossils, etc., throw 

 light upon the conditicnis of their formation and though re- 

 peated for every locality in the State where a certain geologi- 

 cal formation occurs each one Avould have its especial value in 

 comparison with the others as determining- difference in con- 

 dition during formation at such various localities. Moreover 

 the immense changes in chemical composition between contigu- 

 ous strata of dift'erent formations and even in ditl'erent strata 

 of the same geolog-ical age indicate some striking change of 

 physical conditions in the waters from which such rocks were 

 precipitated, changes which we may neAer be able to discover 

 but which must apparently l>e approached from the chemical 

 .standpoint and for Avhich very complete series of determina- 

 tions for related rocks must be essential. 



