A COMPLETE ANALYSIS OF SYDNEY WATER. 153 



potassium. The total filtrates corresponding in all to 21 

 litres of the original water were combined and after con- 

 centration freed from phosphate (by removing as the lime 

 salt) and the potassium precipitated as platino-chloride 

 and weighed as such. The filtrate from the potassium 

 platino-chloride was evaporated to dryness, and the residue 

 tested spectroscopically for lithium without any being 

 detected. 



Barium and strontium— 50 litres were evaporated to 

 small bulk and after filtering, the residue was tested for 

 barium and strontium by fusing with sodium carbonate, 

 extracting with water, and washing until the filtrate was 

 free from sulphates. The undissolved portion was treated 

 with a little dilute hydrochloric acid, strong hydrochloric 

 acid added, and tested spectroscopically for both metals, 

 with negative results. 



Lithium— The filtrate from the 50 litres was made up to 

 500 cc. and 200 cc, equivalent to 20 litres of tne original 

 water, were evaporated almost to dryness, strong hydro- 

 chloric acid added, and examined by means of the spectro- 

 scope. No trace of lithium could be detected. The absence 

 of lithium was confirmed by testing the alkalies by means 

 of the spectroscope. 



Bromine and iodine— The remaining 300 cc. of the above 

 solution — equivalent to 30 litres of the original water — 

 were concentrated until a moist saline mass remained. 

 This was repeatedly extracted with 96°/° alcohol, and the 

 liquid, after the addition of three drops of 20°/° potassium 

 hydrate, was evaporated to dryness. The residue thus 

 obtained was treated twice in the same manner, and the 

 final residue after being heated to dull redness was dissolved 

 in water, mixed with chloroform, and a weak solution of 

 chlorine water added drop by drop, shaking well after each 

 addition. No violet colour being given to the chloroform 



