220 Proceedings of the Asiatic Society. [Oct. 



would excuse him if he asked : 1st. What was the exact result ar- 

 rived at from all Mr. Waldie's analyses ? 2nd. If Mr. W. felt satis- 

 fied that the observations now described, corroborated those detailed 

 in his former communication ? 3rd. What was the largest quantity 

 of organic matter Mr. Waldie had at any time, either during the past 

 month or previously, been able to detect in Hooghly water ? 



Mr. W. replied, 1*4 grs. of organic matter per gallon was the largest 

 quantity he had detected. 



Dr. Smith then expressed his opinion on certain parts of the paper. 



He stated his belief that, to have accurate and precise knowledge 

 of the quantity of organic impurities in any water, such water ought to 

 be analyzed without delay after being drawn. He believed the fact 

 was an accepted one among chemists, that by keeping the foulest 

 water, its organic impurities in time disappeared to a great degree, 

 if not altogether, by the action of the oxygen of the water itself. 



Mr. Waldie's specimens had some of them been kept so long as 

 four months, and none (?), had been examined within less than a 

 fortnight of the time that they were drawn from the river. This 

 might be regarded as a most serious objection to the value of the 

 analyses that had been instituted by Mr. Waldie, and of the conclu- 

 sions drawn from such analyses. 



Again, if Dr. S. was right in understanding that Mr. Waldie had, 

 during the past month, analyzed mixtures of various kinds of water 

 which he himself had artificially produced, and that from these (as 

 being certainly more tainted than our river water) he had arrived at 

 the conclusion that our river water was comparatively pure, and indeed 

 much more so than had been laid down by Dr. Macnamara — if Dr. S. 

 was correct in these premises, he could not but regard such experi- 

 ments as very inconclusive, inasmuch as what was wanted was 

 simply an analysis of the river water recently drawn, (whatever 

 might be its qualities) and not a table showing the composition of 

 mixtures which Mr. W. had made up in his Laboratory — by adding 

 to certain ordinary water a certain quantity of offensive fluid taken 

 from a drain in town, and again a certain quantity of water from the 

 impregnated Salt Lake. 



Mr. Blanford had stated that he was led to understand that a source 

 of fallacy might be attributed to the faulty manner in which Dr. 



