22 JOURNAL OF THE 



zirconate, leaving the latter undissolved. This is dissolved 

 in dilute hydrochloric acid and evaporated several times 

 to dryness with fresh amounts of acid in order to drive off 

 the hydrofluoric acid. The separation b}- means of water 

 is far from perfect, some of the zirconate going into solu- 

 tion, though not enough, usually, to make it worth while 

 to attempt to regain it. There is a good deal of silica left 

 with the undissolved portion. This is separated after 

 evaporation to dryness. The dried mass is reached with 

 dilute hydrochloric acid. There is difficulty sometimes in 

 extracting all of the zirconium chloride in this way. Of 

 course the solution contains large quantities of salt, besides 

 other substances. Zirconium hydroxide is precipitated 

 away from these by ammonium hydroxide, and then thor- 

 oughly washed in large jars by decantation. The crude 

 zirconium hydroxide is next dissolved in strong hot hydro- 

 chloric acid, using as small an amount as possible. This 

 solution is evaporated to dryness and the crude zirconium 

 chloride obtained placed in a large funnel and washed with 

 a mixture of strong hydrochloric acid and four parts of 

 alcohol. This mixture is poured upon the mass in the 

 funnel and allowed slowly to drain through. Some zir- 

 conium chloride is dissolved, but can be recovered by 

 evaporation. The mass in the funnel is left white and 

 fairly pure. To complete the purification this mass is 

 taken an^ repeated!}' crystallized from boiling hydrochloric 

 acid until the acid gives no test for iron, which seems the 

 most persistent among the impurities. I have commonly 

 found it well to repeat this crystallization more than twenty 

 times. The pure oxychloride is gotten in well- formed crys- 

 tals of glistening whiteness. This method of crystallizing 

 from hydrochloric acid, used by Ivinnemann, is the only sat- 

 isfactory one for purifying the zirconium chloride. I have 

 tried the precipitation by hydrogen dioxide, as recom- 

 mended by Bailey, but the consumption of pure dioxide is 



