18 AMERICAN MINERAL WATERS. 



the bicarbonic acid ion is not present in sufficient quantity to balance 

 all the residual calcium, the remaining calcium is combined as cal- 

 cium silicate, and the manganese, iron, and aluminum are calculated 

 to the oxids of manganese (Mn 3 4 ), iron (Fe 2 O 3 ), and aluminum 

 (A1 2 O 3 ), respectively. It was at first thought desirable to omit the 

 statement of results in the form of the hypothetical combination as 

 suggested by Haywood, 1 but inquiry revealed the fact that to do so 

 would materially decrease the value of the work for physicians 

 and others who have been in the habit of interpreting a water 

 analysis only in terms of the salts supposedly held in solution. In 

 recognition of this fact the hypothetical combinations have been 

 inserted. It should be remembered, however, in interpreting the 

 results of the chemical analysis that no claim is made that the several 

 salts do exist in the exact proportion as given, but that with the ions 

 as stated in any particular case their most probable combination as 

 salts would be as given in the hypothetical statement of results. 



The data which were found concerning previous analyses are given 

 under the heading "Advertised analyses." Whenever possible, the 

 name of the analyst is stated. If no advertised analysis could be 

 obtained, analytical data from either Crook or some other published 

 report was used, the source in each case being quoted. The original 

 data have been recalculated to a uniform basis of parts per million and 

 restated as ions. The hypothetical compounds have been calculated 

 also from these ions to conform to the scheme outlined on page 17. 

 This change of statement was necessary for purposes of comparison 

 with the author's results, which conform to the most approved 

 method of stating water analyses. 



The statement of the sanitary analysis complies with the custom- 

 ary form among chemists of reporting these results, and a complete 

 description of the bacteriological methods and a statement of the 

 results obtained are given in a special section on the subject (p. 22). 



CLASSIFICATION OF WATERS. 



A prime requisite in an investigation of this character is some good 

 scheme of classification. This is especially of importance to com- 

 mercial interests, as well as to people interested in the scientific 

 aspect of the work, for by such a classification waters of similar 

 character may be brought together for easy study and comparison. 

 Numerous classifications of mineral waters have been suggested. 

 Indeed, it would almost seem that each person giving special attention 

 to this subject has adopted a new classification formulated by himself. 

 This is undoubtedly due to the complexity of the subject, no one 

 classification seeming to meet all requirements. The arrangement 

 may be chemical, therapeutic, geological, or geographical, the first, 

 however, being the most scientific and satisfactory. The classifica- 



1 Loc. cit. 





