BAILEY. | Methods of Calculation. 93 
in regard to all waters examined we must know the actual spe- 
cific gravity, and take that specific gravity into consideration in 
making our calculations. We have adopted the system of ex- 
pressing the results in grams per liter, also, looking hopefully 
to the time when this nation will follow other civilized nations 
and adopt the metric system as the only legal system of weights 
and measures. 
Grains in a Gallon.—It unfortunately happens that in this 
country people have adopted the habit of representing the 
composition of mineral waters in terms of grains per gallon. 
The physician and the ordinary reader who is interested in 
sanitary matters have become accustomed to this, and they 
find difficulty in interpreting the results stated in any other 
way. Therefore, in deference to this fact, results are also ex- 
pressed in grains per United States gallon of 231 cubic inches, 
as represented in the last column. 
There is, however, unfortunately still a disagreement as to 
the actual relation of grains per gallon to grams per liter. It 
is hoped that this disagreement among authorities will be 
speedily reconciled. As an example of what some of the best 
authorities have used as a factor to express this relation, it is 
noticed that Professor Mason has used the factor 58.3349, Pro- 
fessor Chandler 58.318, Dr. A. C. Peale, of the United States 
Geological Survey, prefers 58.41, Prof. W. R. Nichols has used 
58.37, Prof. Paul Schweitzer in his late report” recommends 
58.41, and Professor Brockett uses the factor 58.372. 
In the calculations in this volume the factor 58.41 has been 
employed. 
39. Mo. Geol. Surv., vol. III, Mineral Waters, 
