MEDICINAL VALUE. 15 



are due to organic nitrogenous matter which is in active state of 

 decomposition or to nitrogenous matter which has been oxidized in 

 times long past and is therefore no longer injurious. In either case, 

 however (especially the latter), the existence of one water containing 

 predominating quantities of nitrates necessitates a classification to 

 cover this group of waters. The medicinal action of these waters has 

 not been determined. 



Acid waters. This group of waters is principally composed of the 

 ferruginous-aluminic sulphated class, although there are a few acid 

 springs which contain comparatively little iron and aluminum, but 

 quite large amounts of calcium, sodium, or magnesium. These 

 waters are used in relaxed conditions of the mucous membrane, 

 especially when characterized by diarrhea or dysentery. They are 

 also used in the treatment of exhausting night sweats and impoverished 

 conditions of the body brought about by intemperance or specific 

 diseases. Locally they are used in treating inflamed or relaxed con- 

 ditions of the mucous membrane such as are found in conjunctivitis, 

 chronic vaginitis, etc. The ferruginous waters of this group have 

 the usual effect of all iron waters, such as has already been described 

 under ferruginous carbonated alkaline waters. When a water is 

 desired for its tonic effect it is best to give it in the ferruginous car- 

 bonated form, since it is more easily absorbed and assimilated. 



Jodie and bromic waters. Since iodin and bromin usually accom- 

 pany each other in mineral waters, they should be considered together. 

 Waters of this class act as alteratives. They stimulate the lymphatic 

 system to greater activity and promote absorption in all the tissues. 

 Their employment is therefore indicated in the treatment of scrofula, 

 syphilis, goiter, chronic exudations, etc. They also favor the elimi- 

 nation of mercury and other metallic poisons. The bromic waters 

 also act as sedatives. 



Arsenic waters. These waters act as an alterative, increase the 

 appetite and digestion, and improve the whole nutrition of the body. 

 They do this not only by increasing the secretion of the gastro- 

 intestinal membrane, but also by checking katabolism. Such waters 

 as these are especially valuable in the treatment of anaemia and a 

 number of skin diseases. They are also indicated in the treatment of 

 chronic malarial poisoning, neuralgia of anaemic origin, scrof ulosis, etc. 



Siliceous waters. The medicinal value of these waters has not been 

 thoroughly investigated, although one or two investigations have been 

 made which seem to show that they would be of value in the treatment 

 of cancer. It has been stated that silica taken internally has caused 

 albumin and sugar to disappear from the urine. 



Azotized and oxygenated waters. Both nitrogen ana oxygen are 

 present in all waters that have come in contact with the air. On 



