the River Severn at Worcester \ 255 



opalescent, and of a distinctly yellowish-brown colour when seen 

 through a depth of 2 feet. It also was alkaline. 



At this time I became aware that Hawford Brook or the 

 river Salwarp, which falls into the Severn nearly 2 miles above 

 the points at which the previous specimens had been taken, re- 

 ceives the surplus water of the Droitwich Canal, which renders 

 it occasionally so salt as to destroy the freshwater fish which it 

 contains. This little stream being thus evidently an important 

 contributor of the chloride of sodium which the water at Worcester 

 contains in such abundance, I was desirous of comparing the com- 

 position of the river at points above and below its influx ; and for 

 the opportunity of doing this I am indebted to the kindness of 

 Martin Curtler, Esq., of Worcester. On the 14th of February, 

 1867, Mr. Curtler rilled several bottles for me from midstream 

 at a point rather more than half a mile above the confluence 

 of Hawford Brook with the river, and then driving down the 

 river's course he collected another specimen at Bailey's Ferry. 

 The difference between these may therefore be expected to ex- 

 press the exact influence of Hawford Brook. For about a fort- 

 night previous to this time the whole of the country bordering 

 the Severn about Worcester had been under water, in conse- 

 quence of the melting of the accumulated snow; but on the 

 14th the river had just retreated to its channel; it was still very 

 turbid, and both specimens on standing deposited about an equal 

 amount of sediment. An analysis was made of the deposit 

 yielded by the water taken above Hawford Brook, which has 

 been already compared with the sediment of April. Both por- 

 tions of water remained opalescent, and of about the same tint 

 of yellowish brown as the water of April, and they both had an 

 alkaline reaction. 



The analysis of these waters has been conducted according to 

 the usual methods. In the water of April, which I collected 

 myself, I precipitated the carbonic acid by calcic chloride and 

 ammonia; the result was similar to that which I obtained in 

 September 1857, and showed that in the Severn, as in many 

 mineral Waters, the total quantity of carbonic acid present falls 

 rather short of the amount required to meet the demands of 

 those bases which must be calculated as acid carbonates. The 

 deficiency of carbonic acid is doubtless in this case supplemented 

 by the considerable amount of silicic acid which is present, of 

 which the greater part is in combination or solution — although 

 a certain portion doubtless exists as an ingredient of the sus- 

 pended matter, which gives rise to the opalescence of the water. 

 This opalescence wholly disappears after protracted rest ; but 

 the great diminution of organic matter which accompanies the 

 clearing leads to the supposition that, probably in the form of an 



