T II E 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FOURTH SERIES.] 



OCTOBER 1867. 



XXXIII. On the Water of the River Severn at Worcester. By 

 Augustus Beauchamp Northcote, M.A. } F.C.S., late Rad- 

 cliffe Fellow in the University of Oxford*. 



INVESTIGATION into the constituents of the water of rivers 

 is of considerable importance in chemical geology, as it not 

 only affords some explanation of the action of meteoric water 

 upon the rocks of the country which they drain, but also shows 

 the nature and amount of the substances which they carry to 

 the sea, by which both its composition and that of the sedimen- 

 tary rocks now forming must be affected. To attain their full 

 value, however, such investigations should be made upon a scale 

 which it seldom falls within the power of an individual to accom- 

 plish : it is not sufficient to analyze a river-water at a given spot, 

 even though this be done at different periods of the year ; for 

 rivers of considerable length must vary both in constituents and 

 in their degree of dilution as their successive tributaries join 

 them, since it is most unlikely that the rocks of the entire dis- 

 trict which they traverse should present uniformity of composi- 

 tion. It is indeed an easy task to ascertain the substances which 

 the water of a river pours into the sea, by analyzing a specimen 

 taken at such a distance from the river's mouth as to ensure its 

 freedom from admixture with sea-water; but to obtain anything 

 approaching to a complete knowledge of the action which me- 

 teoric water exerts upon the rocks which form the river's water- 

 shed, water taken from various well-selected points ought to be 



* Communicated by the Author. 

 Phil. Mag. S. 4. Vol. 34. No. 230. Oct. 1867. S 



