48 OX TINKALZITE (BORATE OF LIMB AND »ODA), FROM PERU. 



The analysis of the mineral in question has given me the following 

 result, by the side of which I have placed the analysis of M. Kletzinsky :— 



American Tinkalzite, African Tinkalzite. 



Phipson. Kletzinsky. 



Water 34-00 37-40 



Soda 11-95 10-13 



Lime 14-45 14"02 



Boracic Acid ... 34-71 36"91 



Chlorine .... 1-34 133 



Sulphuric Acid . . 1-10 0-50 



Silica 0-60 „ 



Sand 2-00 „ 



Phosphoric Acid . traces „ 



Alumina .... „ „ 



Magnesia .... „ >, 



100-00 100-00 



The difference in the quantities of water, as shown in these two 

 analyses, is owing to the gradual loss of water by soda-salts when exposed 

 for some time to the air. 



By neglecting the accidental elements, and calculating the water, soda, 

 lime, and boracic acid, we arrive at the formula — 



(Na O, 2 Bo s 4- 10 HO) + 2 (Ca O, Bo s 4- 2 HO) 4- 2 HO. 

 Borax. Borate of lime. Water. 



The presence of the other substances given by analysis seems to indi- 

 cate that this mineral has been formerly deposited by mineral springs ; 

 and the fact that the biborate of soda it contains has crystallised with 10 

 equivalents of water, shows that the temperature of these springs could not 

 have been greater than 4- 55° (Centigrade). As it is imported from 

 America for industrial purposes, tinkalzite contains about 60 per cent, of 

 borax, 25 per cent, of borate of lime, and 2^ per cent, of chloride of 

 sodium. It forms an excellent flux for metallurgical purposes, and has 

 been employed with success in the porcelain manufactories of Sevres by 

 M. Salvetat. In fact, it appears capable of effectually replacing borax in 

 all the applications of this rather expensive salt to industrial or manufac- 

 turing processes. 



To extract boracic acid from tinkalzite, a given quantity of hydrochloric 

 acid is diluted with water, and saturated while boiling with the pulverised 

 mineral ; the clear solution is decanted while hot, and, upon cooling, the 

 liquid throws down the boracic acid in large quantities. 



