122 



Mr. Waldies Investigations connected 

 Table III. 



[No. 2, 



Kiver water of 5th October, 1866, Ebb 

 tide, cleared by a little hydrochloric 

 acid and filtered, 



R. W. of 10th October, Flood, filtered, 



R. W. of 10th Nov. Flood, filtered, 



R. W. of 19th Nov. Ebb, Surface, ... 



Beep, 



R. W. 15th Feb. 1867, Flood, 

 Dalhousie Sq. Tank W. of 9th Oct.1866. 



General's Tank, of 6th Feb. 1867, .., 

 Baranagar Tank, of 1st Oct. 1866, ... 

 Ditto, of 15th Feb. 1867, 





Oxygen 



Time of trial. 



req. for 





100,000 





grs. 





grains. 



5th October, 



.1430 



7th 



.0440 



10th October, 



.1210 



12th „ 



.0860 



10th November, 



.1210 



12th „ 



.0860 



19th, \ hour old, 



.1390 



20th „ 



.0357 



23rd „ 



.0332 



19th, J hour old, 



.0640 



20th „ 



.0320 



23rd „ 



.0345 



15th, 2 hours old, 



.1125 



16tb, 28 hours old, 



.0410 



9th, 3 hours old, 



.1425 



10th, 16 hours old 



.0860 



2nd November, 



.0430 



7th, 3 hours old, 



.2830 



7th, 26 hours old, 



.1155 



1st October, 



.3150 



2nd „ 



.2740 



15th, 1 hour old, 



.4755 



16th, 25 hours old, 



.3625 



This table exhibits very plainly the rapid diminution of the amount 

 of oxygen required, by keeping even for one day, and the more gradual 

 diminution afterwards. I have not observed that any notice has been 

 taken of this circumstance by the English chemists. Dr. Macnamara 

 first directed my attention to it, and since then I have not only made 

 many observations of the fact, but have also made experiments as to 

 the cause. The analyses of the London waters published monthly 

 are of the waters supplied by the water companies, therefore, all 

 probably two or three days old. It is evident that in the recent 

 water, there must be substances possessing active deoxidizing properties, 

 which speedily undergo certain changes by which they lose these 



