[sHUTT & SPENCER] MINERAL CONSTITUENTS OF OITAWA RIVER 179 

 III. Results of Analysis combined as they probably exist in the river water. 



KCl 



Na,SO,.... 

 Ca, (POJ,. 

 Na HCO3. . 

 Ca (HCOs)^ 

 Mg (HCO3) 



SiO^ 



Al.O^ 



Fe.Oa 



Mnj 0^ 



July 15th 

 1907 



p.p.m. 

 1.05 



4.45 



.94 



.54 



22.17 



10.10 



7.06 



.52 



.70 



.86 



48.39 



8.18 p.p.m. were present. The smaller amount on the latter date is 

 possibly due to the higher temperature of the water at that time — which 

 would necessarily mean a greater decomposition of the bicarbonates of 

 the water with precipitation of the lime as mono-carbonate. The 

 magnesia is also lower in July than in March, and probably for the same 

 reason. 



The silica content is approximately the same for both samples, and 

 constitutes somewhat more than one-fourth of the total mineral matter. 



To quote from Dr. Daly's letter acknowledging our results, " The 

 analyses show clearly the small content of calcium in the Ottawa river 

 water and suggest that the pre-Cambrian ocean received far less calcium 

 from the inflow of rivers than the present ocean receives for the same 

 volume of inflow. Your analyses show that the River Ottawa annually 

 delivers to the St. Lawrence and the sea, per volume, only 20 per 

 cent of the amount of calcium now annually delivered to the sea by the 

 average river of the globe. If (as is very probable) the pre-Cambrian 

 lands were much smaller in area than the total of the present continents, 

 the annual receipt of calcium by the pre-Cambrian ocean may have been 

 much less than the 20 per cent, possibly only 10 per cent or less." 



" These estimates suggest that the animals had relatively little 

 calcium for the " manufacture " of hard parts in the pre-Cambrian time. 



Sec. III., 1908. 12. 



