5<S6 MIXERAL Srkl.NC AT RlETFuNTEIN. 



barium hydrate, and loo.ooo c.c. of water contain i .6720 gram of 

 free and combined carbon dioxide. 



The combined carbon dioxide can Ije calcnlated froni the 

 alkalinity-determination. 



100,000 c.c. contain 1 .86.S89 grams of HC( ),.,, i.e., 1.3479 

 gram.s of conii)ined carlion dioxide. 100.000 c.c. of the water 

 therefore contain 0.3241 of a gram of free carbon dioxide. 



O.vygc)!.- -'['hi: oxygen was determined by Winkler's iodo- 

 metric method. A stoi^pered bottle \va.s completely filled with 

 water, 2 c.c, ])ipetted oil', arul replaced by 1 c.c. of manganous 

 chloride solution, and 1 c.c. of an alkaline ])Otassitim iodide solu- 

 tion. A brown precipitate of hydrated manganese dioxide is 

 formed, which dissolves on addition of hydrochloric acid, liberat- 

 ing iodine from the ])otassium iodide, 'idle iodine is titrated witn 

 sodium thiosuli)hate. 



100,000 c.c. of water were thus found to contain o.o()i5 

 of a gram of oxygen. 



* The water was collected under a ];ressure of 661 mm. and 

 registered a tem])erature of 2^)^ . Under these conditions one 

 litre (jf distilled water dissolves approximately 4.66 c.c. (re- 

 duced to X.IM'. ) of (jxygen. The weight of oxygen soluble 

 in 100 litres of distilled water, and under a ])ressure of 661 mm., 

 is 0.67 of a gram, an amount v\hich is considerabl}' in excess of 

 that determined for the s])ring water. 



It appears, therefore, that the water has considerable oxy- 

 gen-absorl)ing ])ower. This was conse(.|tiently determined by 

 titration with alkaline ])er!nanganate. In two determinations 



N 

 the amounts of — ])Otassiuui permanganate absorbed by 100 c.c. 



10 

 of water were respectively 3.00 and 3.07 c.c. 



Sulphuretted Hxdrugen. — In the bath-house there is an 

 oj^i^ressive smell, resembling stiljjhur dioxide. The amount of 

 this gas in the atmosphere, if ])resent at all, nutst be extremelx 

 small, as seven litres of air siphoned through distilled water 



X 



containing 10 drops (0.2c/ c.c. of iodine-starch solutiou. 



too 

 produced no noticeable change in the colour intensity. In view 

 of the alkaline reation of the water it is scarcely likely that the 

 sul]jhur dioxide will be dissolved as such; moreover (|ualitative 

 tests for sui])hites with strontium chloride, sodimn nitroprusside. 

 and zinc suli)hate, as well as with gold chloride, gave negative 

 results. It is thought possible that the sulphm- dioxide may be 

 derived from sulphuretted h)(lrogen dissolved in the water, 

 although the latter could not be irlentitied (iualitatively by means 

 of an alkaline solution (<f lead acetate with Rochelle salt. The 

 water, however, discolours iodine solution, and the results are 

 calculated tentatively as sulphuretted hydrogen, although the 

 discolouration of iodine ma_\ be due to the reducing ])ow er of the 



