ENVIRONMENT AND REGENERATION 469 



Residue on evaporation: 



Total solids 38 to 42 parts per million 



Alkilinity as calcium carbonate: 



Methyl orange to parts per million 



Chlorides: 



As sodium chloride to parts per million 



Ammonia nitrogen 4 to 7 parts per million 



Albuminoid nitrogen 0.060 to 0.102 parts per million 



A conunon shiner (Notropus blennius) lived in this water, changed 

 weekly, from October 18, 1917, to February 17, 1918, or a total 

 of one hundred twenty-two days. As, during this time, the fish 

 decreased notably in size, its death might be attributed to star- 

 vation rather than to the toxicity of the water. Powers (unpub- 

 lished) has shown that two goldfishes lived in this water ninety- 

 five and ninety-nine days respectively, whereas in ordinary 

 distilled water the length of life was three hundred fifty-two 

 and five hundred and ninety-seven minutes. 



All chemicals used were either Mercks' or Baker's analyzed 

 chemicals. The acids and bases were standardized at O.OIN, 

 except H3PO4, Na2C03, and NaHCOs, which were 0.01 mol. 



For the determination of CO2 production, 1-pint clamp-top 

 fruit jars were used. The capacity of one of these jars is about 

 500 cc. Four hundred cc. of water or the solution under inves- 

 tigation was put in a jar, then a test-tube containing 10 cc. 0.02N 

 Ba(0H)2 was inserted so that the top of the test-tube stood 

 above the level of the water, the rubber ring was adjusted, the 

 tadpole put in, and the lid clamped down. A stronger solution 

 of Ba(0H)2 was used where acid had been added to the water 

 or where more CO2 was expected. To correct for the CO2 in 

 the water and in the air above, a control jar was prepared at the 

 same time and in precisely the same manner, except that no 

 tadpole was put in, and placed beside the experiment. At inter- 

 vals, usually 24 hours, the Ba(0H)2 was mixed with the water 

 by inverting and rotating the jar, the tadpole was quickly re- 

 moved, and the excess of Ba(0H)2 titrated with O.OIN H2SO4, 

 using phenolphthalein as indicator. The difference in the 

 amount of acid required to neutralize the experiment and the 

 control was recorded as the amount of CO2 (as O.OIN H2CO3) 



