ANALYSES OF THE OTTAWA RIVER 



159 



42.4, 48.8, 62.4 parts per million, and solids after ignition (December 22, 

 1887, not determined), 34.0, 28.0, 22.8, 36.4 parts per million. The 

 figures average 52.4 parts per million for total solids and 30.3 parts per 

 million for solids after ignition. It will be seen that the variation in 

 each of the two quantities from year to year and from season to season is 

 relatively small; hence we may conclude that the two 1907 analyses fairly 

 represent the average nature of the Ottawa river water in modern times. 

 The content of calcium and magnesium of the two stages of the river, 

 and their mean have been calculated to parts per million and the results 

 entered in table III, which also gives, for purposes of comparison, the 

 calcium content of other rivers, as well as of the Ottawa river at Sainte 

 Anne rapids below the solid block of Paleozoic limestones lying between 

 Ottawa and Montreal. The references for the original publications of 

 these latter analyses may be found on page 60 of Bulletin number 330 

 of the United States Geological Survey. 



Table III. 



River. 



Terrane. 



Calcium. 



Magne- 

 sium. 



Ratio < f 

 Ca to Mg. 







Parts per 



Parts per 





Ottawa — 





million. 



million. 





a. Low water 



Late pre-Cambrian 



ditto 



8.98 

 5.84 

 7.41 

 9.92 



2.35 

 1.67 

 2.01 

 2.02 



3.50 : 1 



b. High water 



3.82 : 1 



c. Mean of a and b 





3.69 : 1 



d. Sainte Anne 



Late pre-Cambrian and 

 early Paleozoic. 



4.91 : 1 







Average of four Swedish 



Late pre-Cambrian 



6.88 



1.52- 



4.52 : 1 



rivers and Ottawa and 











Pigeon rivers. 











Saint Lawrence at Ogdens- 



Late pre-Cambrian and 



32.05 



7.21 



4.44 : 1 



burg — a verage of 6 



Paleozoic. 









monthly analyses. 











Mississippi — 











a. At Minneapolis— av- 



Late pre-Cambrian and 



41.18 



15.34 



2.69 : 1 



erage of 23 analyses. 



early Paleozoic. 









b. Memphis — analyses 



Late pre-Cambrian and 



34.38 



13.75 



2.50 : 1 



of 1 7 composites. 



Paleozoic chiefly. 









c. New Orleans — aver- 



Nearly average conti- 



33.90 



8.65 



3.92 : 1 



age of 52 composites. 



nental mass of present 

 time. 









Danube— average of 23 

 analyses. 





43.89 



9.94 



4.42 : 1 











Rhone — average of 5 anal- 





44.91 



6.22 



7.22 : 1 



yses. 











Seine 





73.99 

 33.85 



1.60 



7.75 



46.24 : 1 



Average of 19 rivers (Mur- 



ditto 



4.37 : 1 



ray). 7 











Average of 44 rivers 



. . ; . . .ditto 



37.77 



9.03 



4.18 : 1 









7 Sir John Murray : Scottish Geographical Magazine, vol. 3, 1887, p. 65. 



