262 Gooch and Cole — Chlorine in Haloid Salts. 



of bromine up to 0*3 grm. (0*5 grm. of potassium bromide) 

 associated with 0*25 grm. of chlorine combined in the form of 

 chloride (0*5 grm. of potassium chloride). 



According to the procedure found to be effective, the haloid 

 salts are introduced into the Voit distillation flask with 1 grm. 

 of telluric acid. The volume of liquid is made up with water 

 to 40 cm \ The distillation flask and the inlet tube of the 

 receiver, the latter charged with 300 cmS of a 1 per cent solution 

 of potassium iodide, are connected after moistening the surface 

 of the ground-glass joint with sulphuric acid to serve as a 

 lubricant and lute. The sulphuric acid, 10 cm3 of the [1:1] 

 mixture, is introduced through the separating funnel. Carbon 

 dioxide is passed very slowly through the apparatus and the 

 reaction mixture is boiled until the meniscus of the liquid is at 

 a level about mid-way between the 20 ctn3 and the 15 cm3 marks, 

 indicating a volume of 17 cra3 or 18 c#m3 . The source of heat is 

 withdrawn and, as soon as the apparatus is cool enough to be 

 handled conveniently, the receiver is disconnected and the free 

 iodine in the receiver and trap is titrated with standard sodium 

 thiosulphate and taken as the measure of the bromine liberated. 

 By the procedure described it is possible to determine with a 

 high degree of accuracy any amount of bromine up to 0*3 grm. 

 when associated in the haloid salts with amounts of chlorine up 

 to 0*25 grm. The entire operation need not occupy more than 

 forty-five minutes. 



Art. XX.— Wilkeite, a New Mineral of the Apatite Group, 

 and Okenite, its Alteration Product, from Southern Cali- 

 fornia ; by Arthur S. Eakle and Austin F. Rogers. 



WlLKEITE. 



Occurrence. — One of the most interesting mineral occur- 

 rences of Southern California is situated at Crestmore, about 

 eight miles west of Riverside, in Riverside County, where a 

 contact zone exists between crystalline limestone and grano- 

 diorite. The Riverside Portland Cement Company is now 

 quarrying the limestone, with its associated lime silicates, for 

 the manufacture of cement, and the extensive quarrying of 

 the hill of limestone and granodiorite is constantly bringing to 

 view varied and interesting associations of metamorphic 

 minerals. 



Much of the limestone is snow-white marble quite free from 

 included minerals other than patches of pure white wollaston- 

 ite, but on the northeast side of the hill the metamorphism has 



