JOURNAL 



OF THE 



ASIATIC SOCIETY, 



Part ] L— PIIYSICxYL SCIENCE. 



No. I.— 1867. 



Experimental Investigations connected loith the supply of water 

 from the Hooghly to Calcutta, Part II, being Supplementary 

 Observations ; by David Waldie, Esq. F. C. S. dx. 



[Received 28th September, 1866.] 



In the preceding remarks I have directed attention to the discre- 

 pancies between my own results as to the quantity of organic matter 

 by weight in the Hooghly water and those given in Dl\ Macnamara's 

 Report, and I have also made some pointed observations on the very 

 doubtful accuracy and unsatisfactory nature of the results generally 

 given by chemists respecting organic matter in waters, except some of 

 the most recent. For though I have found that the process detailed 

 in the previous part of m} r paper is older than I then supposed, having 

 been recommended by Mr. Dugald Campbell in 1850 as suggested by 

 Ih . Clark,* and that an analogous plan was given by Abel and Bloxam 

 in 1854,f though imperfect, yet these plans seem either to have been 

 little known, or neglected, or imperfectly earned out. Some analysts 

 indeed of later date do not even attempt to estimate the amount of 

 organic matter at all, apparently despairing of reliable results. But 

 the process given, I believe, yields the most trustworthy results 

 hitherto obtainable, if properly performed. 



* Journ. Chem. Soc. Vol. IX. 1856, p. 51, 

 f Handbook of Chemistry, 1854. 



