WATER ANALYSES. 117 



NOTE ON THE CHEMICAL CONSTITUTION OF FISHING 

 WATERS, AND OF THE IRWELL. 



BY CHARLES ESTCOURT, F.I.C., F.CS. 



Believing the subject to be of considerable importance, not merely as 

 indicating the effect of purity as contrasted with impurity in our rivers and 

 streams, but also in connection with the natural history of fish, I have 

 undertaken for the Association a series ot analyses of famous or well-known 

 fishing waters. As the Association has a sort of proprietary right in one 

 river (the Dovey), I have begun operations with that river. 



Two samples were taken from it on the same day (September lo), and 



within twenty minutes of each other at the same spot, just below Dinas 



Mawddy. They presented the following difference in constitution, caused 



by the fact that the river was clean and low when the first sample was taken, 



and that, owing to a sudden thunder storm, it had become milky white, and 



had risen three inches when the second was procured. 



DOVEY. 



BEFORE AFTER 

 RAIN. RAIN. 



Grains per gallon. 



Total solid matter 2'38 ... 3'io 



Mineral Matter I'lO ... no 



Suspended Matter o"oo ... 72 



Loss on Ignition i"28 ... i"2S 



■^ -, ' 



Hardness, Degrees i"8 



Chlorine '53 



Ureal Ammonia o'oooy 



Alb'J ditto 0-0042 



It will be perceived that the only difference between the milky and 



transparent condition of the river may be represented by the total solid 



matter. The milky sample holds in suspension only 072 of a grain per 



gallon, notwithstanding its great show of muddiness. It may not be 



uninteresting to compare with the Dovey, two Manchester waters, one pure 



and the other polluted. 



Thirlmere. The Irwell. 



Total Solid Matter 3'io ... 4830 



Mineral i'i5 ... 3500 



Suspended Matter o'oo ... ii'2o 



Loss on Ignition i'95 ... 1330 



Hardness 1-50 ... 1600 



Chlorine 0'44 ••• 526 



Ureal Ammonia 0*0009 ••• 03192 



Alb""' ditto 0'0042 ... "1344 



