the Air and Water of Towns. 481 



from the Dee, above Llangollen and below, it appeared evi- 

 dent that even this small town had affected the river. Before 

 the water arrives at Chester the peat predominates too much 

 to make it perceptible that matter from towns has been 

 thrown into it; below it is distinct. Water from surface- 

 drainage indicates by the same mode of treatment nitrogenous 

 matter undecomposed. 



Observing this increase of organic matter on approaching 

 towns, I naturally expected to find a large quantity in the 

 wells, of which there are many in Manchester, j)laced as they 

 often are in the neighbourhood of cesspools, besides beiu"* 

 exposed to the infiltration of the water of drains. 



A well was first examined in a garden near the town, the 

 proprietor having complained of it as being imwholesome. 

 It contained 40 grs. of common salt per gallon, 14 grs. of 

 organic matter and salts of ammonia, besides other ingredients 

 to be expected in connection with organic matter. I next 

 examined a well near a burying-ground ; it was loaded with 

 inorganic salts. Its taste was very bitter ; when evaporated 

 and burnt, the remaining inorganic matter gave out a pun- 

 gent acid vapour. Four wells in the same neighbourhood 

 were examined, all with the same results. I then went to nearly 

 all the churchyards in Manchester, of which there is a consi- 

 derable number, but finding that the neighbourhood of the 

 collegiate church gave the same indications as all the rest, 

 although there have been no burials there for many years, I 

 was induced to ascribe it to the presence of large dung-heaps 

 close to the well. Other wells distant from churchyards, but 

 near cesspools, gave the same result. In the suburbs they 

 were not so much tainted, but in some newly-built streets 

 close to the town, in gravelly soil, were very bad. 



I have no doubt that the churchyards and the cesspools act 

 in a similar manner, as we might naturally expect. The chief 

 impurity is a collection of inorganic salts. It is remarkable 

 how rapidly the organic matter becomes oxidized and con- 

 verted into nitric acid in the soil. In one case I found as 

 much as 70 grs. of nitrates in a gallon of water, besides mag- 

 nesia, lime and alkalies. This water seems to be a favourite 

 with some persons ; when not quite so heavily charged it has a 

 fine sparkling appearance. The wells in the centre of the town 

 have nearly disappeared, otherwise it is probable that organic 

 matter would have been found there in a less oxidized state. 



As these wells have undergone several changes during the 

 autumn and early part of the winter, I shall not give the re- 

 sults of the analyses which I have made, until a few seasons 

 shall enable me to make a more complete examination of the 



Phil. Mag. S. 3. No.20't. Suppl. Vol. 30. 2 K 



