Mr. Waldie's investigations connected 



[No. 1, 



organic matter present. It was impossible of course to get the hot 

 season water in its original condition, but experiments could be made 

 with river and tank water, and with mixtures intended to imitate the 

 real or supposed peculiarities of hot season water. These could be 

 examined to ascertain the amount of change produced on them by 

 keeping. Accordingly experiments were made the results of which 

 are exhibited in the following table. 



Date of collection 

 or preparation. 



Date of Expt. 



For 100,000 jZ. grains W. 

 Organic matter. Oxygen reqd. 



Grains. 



Calcutta Sewage Water. 

 13th Sept. 1866, 13th Sept. 

 14th 



15th 21.80 



17th 

 27th 10.75 



Mixtures of River Water with Sewage. 

 No. 1, containing |th Sewage. 



10th September. 10th Sept. 5.44 



11th 

 15th 



24th 3.63 



25th 

 *2nd October, 

 No. 2, containing ^th Sewage. 

 11th September. 11th Sept. 



12th 2.18 



15th 



24th 1.88 



25th 

 *2nd October, 

 No. 3, containing J Sewage and § Barn. Tank Water. 

 18th September. 18th Sept. 6.05 



26th 2.65 



*2nd October. 



Grains. 



2.300 

 2.040 



1.470 



.535 



.480 



.422 



.624 

 .203 



.245 



.163 



.441 

 .353 



.420 

 .725 



1.938 



* Introduced after date of paper. 



