1896.] Hypochlorites to Chlorates. 77 



sometimes red rays entered. Some of them were exhausted, and some 

 contained air. Several stoppered bottles and flasks were also used, and 

 the experiments lasted for three months. They were dividedinto three 

 sets : — 



(i) Those exposed in orange yellow rays, 

 (ii) Those exposed to ruby rays, 

 (iii) Those kept in absolute darkness. 



The solution in all the three sets of experiments, on examination, , 

 was found to change colour, from colourless and pale yellow to colourless i 

 and distinct pink. Flakes of silica separated in those tubes in which » 

 the contact was prolonged. On shaking, the solution turned milky owing 

 to the separation of minute air-bubles (capable of rekindling a glowing 

 chip of wood — hence oxygen). They, however, disappeared after few 

 minutes leaving the solution clear. The following preliminary experi- 

 ment was performed. 



In a 250 c.c. flask closed with an india-rubber stopper and provided 

 with a delivery tube, 200 c.c. of a strongly alkaline solution of sodium 

 hypochlorite was introduced, care being taken not to allow any trace . 

 of the solution to come in contact with the stopper. The open end of 

 the delivery tube dipped under mercury in a mercurial trough above ; 

 which a measuring tube filled with mercury was placed. The apparatus ; 

 was kept in situ for two weeks. After the expiration of the above period i 

 the solution was examined. Tlie colour did not sensibly change, al- 

 though the temperature varied from 28° to 33° C. No gas was found in : 

 the tube. On shaking, however, minute bubles of gas were liberated, , 

 but the quantity of oxygen was too small to overcome the mercurial 

 pressure. 



10 c.c. original solution contained 0*2191 gram of available chlo- 

 rine of hypochlorite and 0-0045 gram of chlorate, making in all 0'2236 

 gram. The sample contained 0*2245 gram of chlorine (total). Con- 

 siderable difference, however, was observed when the solution was ana- 

 lysed after two weeks, 0*1987 gram of chlorine of hypochlorite and i 

 00242 of chlorate were found. The total available chlorine was thus 

 0*2229 gram, a quantity very nearly the same as before. The experi- 

 ment was repeated with fresh solution, the duratjlon in this case being 

 a week. Exactly similar results were obtained. Liberation of oxygen 

 was beyond doubt. Several other qualitative experiments were made 

 by keeping solutiotis in the so-called condensation tubes provided with 

 stopcocks. All these have led me to the same conclusion. The follow- 

 ing table contains some of the results of the analysis (expressed in 

 gleams). In order to simplify comparison the available chlorine has 

 been expressed in terms of oxygen. 



