34 GEOLOGICAL SURVEY OP WISCONSIN. 



composition (aided by free carbonic acid) of these magnesian lime- 

 stones. Whether the Archaean rocks further north will afford waters 

 of a diflferent class, as seems probable, remains to be determined in the 

 further progress of the survey. 



Waters percolating through the drift that so completely covers and 

 conceals the rocks, are also found to contain chiefly lime and magnesia 

 with smaller quantities of soda, chlorine, iron, etc. These elements 

 are most usually combined with carbonic acid, and are the product of 

 the solution of magnesian limestone almost everywhere existing in 

 the form of boulders, gravel, or calcareous sand. If we take a lime- 

 stone pebble from one of these springs, it will usually be found soft 

 and much decayed upon the surface by the action of the waters, and 

 it would be wonderful indeed if such waters should not contain lime, 

 or if such rocks should not, in the course of ages, be dissolved and 

 carried away. As the carbonate of magnesia is always associated with 

 the carbonate of lime in the rocks, so it is in the mineral waters. In 

 general, the waters are found to partake of the character of the rocks 

 and soils through or over which they percolate or run. 



The figures in this table show the number of parts in one thousand 

 parts (by weight) of the water, which consist of solid matter that re- 

 mains when the water is evaporated. If we do not care to consider 

 minute differences arising from changes of temperature, and the spe- 

 cific gravity of the water, we have only to multiply the figures in this 

 tabic by seven, to find the number of grains in one pint; this product 

 being multiplied by eight will show the number of grains in a gallon. 

 The table shows, without any change of the figures, the number of 

 ounces in a cubic foot of the water. 



This decimal system of stating the results of chemical analyses is 

 adopted in all cases except in regard to mineral waters, where we of- 

 ten find only the number of grains in a pint, a quart, or a gallon. 

 Americans were the first to adopt in currency and coinage this simple, 

 convenient, easily comprehended and labor-saving system, and we 

 should not be the last to apply it in other cases. Its benefits are in- 

 ternational. If we give the number of grains of solid matter in a 

 gallon of water, we use a language understood, perhaps, at home, but 

 not anywhere else; but if we say there are so many parts in every 

 thousand parts of water, we state a fact in a manner that is under- 

 stood in every part of the world. There will be ten grains in every 

 thousand grains; ten pounds in every thousand pounds; ten grams 

 in every thousand grams; and the Frenchman, or the men of 

 any other nation, will not have to search the encyclopedia to find the 

 value of a grain or the size of a gallon in Wisconsin. ls"o matter 



