216 



ON THE ATR AND RAIN OF MANCHESTER. 



mens ; sickly taste begins when the greasy and bitter tastes 

 are gone. 



Alkaline also ; alkalinity lost by boiling. 



Nitrogenous fumes obtained on burning the residue. 



Residue as before, alkaline. 



Timperley, six miles distant. — Abundance of green matter 

 at the bottom of the glass ; an immense amount of green mo- 

 nads, mostly separate, but some in clusters. 



Gave off alkaline fumes when the residue from evaporation 

 was burnt. 



Ash then strongly alkaline. 



This water was strongly alkaline, and was farthest from the 

 town ; it had, however, a great deal of organic matter in it — 

 as much as any — so that the acid seems so far to be a surer 

 guide to the neighbourhood of the town. 



Park-street, outside of the town, south-west. — Matted 

 confervas appeared in this specimen, on standing, with many 

 green spots stationary and in motion. 



The water alkaline, but acid on boiling. 



The ashes neutral. 



We are here therefore still within the town influence, but 

 it appears that in the outskirts of the town the acid is neu- 

 tralized in a great part with ammonia, as the rain does not 

 become acid until that is driven off. 



We may therefore find easily three kinds of air, — that with 

 carbonate of ammonia in the fields at a distance, — that with 

 sulphate of ammonia in the suburbs, — and that with sulphuric 

 acid, or acid sulphate, in the town. 



I need not minutely describe each specimen which I 

 collected ; there is much similarity when from the same 

 district. 



