DISSOLVED CONTENT OF WATER. 899 



it was seen that a continuous stream of minute bubbles of gas was always con- 

 tained in the water issuing from the well. On dippering the water in the jar a 

 marked white cloudiness caused by very minute bubbles appeared after a fraction 

 of a minute. This cloudiness disappeared after a few minutes and the water 

 became quite clear. On dippering again the same occurrence took place, and 

 this could be repeated several times before the water ceased to cloud upon 

 dippering. 



Trout placed in a jar of the water just as it was delivered from the pump 

 were immediately in great distress and within one minute turned over appar- 

 ently suffocated. If then immediately removed to Potomac water, they revived. 

 Trout placed in the well water after dippering it considerably lived a tew hours, 

 but then died. From the behavior of trout in the water and the release of gas 

 from it, it was inferred that the water had a considerable excess of nitrogen or 

 carbon dioxide, or both, and at the same time a very marked deficiency of 

 oxygen. A determination of the oxygen alone showed only 0.2 c. c. per liter of 

 water, while the water was probably capable of taking up from the atmosphere 

 at least 30 times this amount of oxygen. The lack of oxygen accounted for 

 the immediate suffocation of trout. 



By various experiments in exposing the water to the atmosphere, such as 

 allowing a slender jet of it, issuing with considerable force from a glass tube 

 drawn out to a small orifice, to impinge upon the center of the bottom of a tall 

 glass cylinder or battery jar laid horizontally, it was found that brook trout 

 would live in the water thus very thoroughly exposed to air. The introduction 

 of air into the water by means of the usual linden wood liberators accomplished 

 the same end provided there was no renewal or flow of water. It was necessary 

 in the case of a large aquarium full of water to let the air current flow for some 

 time before introducing fish in order to give the water a chance to take up 

 enough oxygen to keep the fish from immediate suffocation while the oxygen 

 content was further increasing. 



The method mentioned above of breaking up in part into spray a jet of 

 water, even when three air liberators were delivering finely divided air into the 

 aquarium which received the water, did not succeed in air saturating the water 

 with oxygen. That is, it did not fill the water with as much dissolved oxygen 

 as it was capable of absorbing from the air. It raised the oxygen content, 

 however, from 0.2 c. c. to 4.6 c. c. per liter. By cutting off the flow of water 

 and allowing the liberators to run air into the tank full of standing water for 

 some 40 hours in the presence of two yearling brook trout the water then held 

 6 c. c. of oxygen per liter at 11.5° C. 



The water was thought of such interest on account of its peculiar air con- 

 tent and other features that a determination of the nitrogen dissolved was 



