68 JOURNAL OF THE 



ties. The streng'tli of this solution was 72 volumes, being" 

 broug-ht to this streng-th according* to Thenard's 

 method"'"'^ (Marchand). I further purified and concen- 

 trated this to 111 volumes by distilling- in partial 

 vacuum, according' to Talbot and Moody.""' I found the 

 potassium sulphate present interfered very much with 

 the reaction by the formation of the more or less solu- 

 ble basic zirconium potassium sulphate. So nothing- 

 definite could be learned from my experiments, which 

 were many, with either the 111 or 72 volume hydrog-en 

 peroxide. 



To avoid the formation of the compound with potas- 

 sium sulphate, hydrochloric acid''* was used. By this 

 method was obtained a solution of the dioxide practi- 

 cally free from silicic and sulphuric acids, but one 

 weaker, being* only 55 volumes. It was with this solu- 

 tion the analyses above reported were made. 



This method of using- hydrog'en dioxide is the only 

 accurate method g-iven'for the separation of zirconium and 

 titanium. 'It is direct and rapid, delicate and eleg-ant, 

 but expensive and by no means always convenient. 



I cannot close this summation without expressing- my 

 g-reat indebtedness to Dr. F. P. Venable, for his ever 

 ready sympathy with and kindness to me in this work. 

 I wish also to express my thanks to Dr. Chas. Mar- 

 chand, 28 Prince st., New York, for six pounds of 72 

 volume hydrogfen peroxide, with which he kindly pre- 

 sented me. 



33. Mass. Inst. Technolog-y Quarterly, V-123. 



34. Ibid, 131. 



32. Anneles de Chemie de Physique, [2] 10-114, 335, 11-85. 



