Chemical Composition of the Thames Water. 



115 



between the 1st of September 1854 and the beginning of the 

 year 1855 ; but it is obvious that this inchides only a quarter of 

 a year, and, moreover, only that particular quarter following the 

 drought and heat of summer and autumn, the effect of the spring 

 rains being altogether omitted. 



The analyses detailed below extended over the whole year^ viz. 

 from May 1855 to May 1856 ; so that from them the maximum, 

 minimum, and mean composition may be deduced for the whole 

 year. 



Two series were undertaken, the one at Kingston, the present 

 source of supply of the Chelsea and Lambeth Waterworks' Com- 

 panies, the other at Chelsea, with the view of comparing the 

 mean composition at these two points : the analyses of the former 

 series were repeated about once a month (and, indeed, during a 

 certain period when great fluctuations took place, once a week), 

 and those of the latter four times in the year, viz. in June, 

 October, and December 1855, and May 1856. 



At the commencement of the inquiry a complete analysis was 

 made at each point, the results of which are given in detail ; but 

 subsequently only the most important constituents were deter- 

 mined, and the analyses are given as the direct results of ^expe- 

 riments (without arranging the acids and bases together), to faci- 

 litate present and future comparison. 



To commence with the composition of the water at Kingston : 

 the following are the results of the original complete analysis. 



This sample was collected at the Chelsea Waterworks Com- 

 pany's new works at Kingston (in common with all the other 

 samples from this point, by my friend Mr. James Simpson, jun.), 

 on the 26th of May, 1855. It had a temperature at the time of 

 62° F. (16°-6 C), that of the air being 63° F (17°*22 C). 



The following are the analytical results : — 



Table a.- — Direct results of Experiments calculated in 1000 

 grains of the Water. 



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