642 SCIENTIFIC EECORD FOR 1883. 



feldspar with sulphuric acid and a fluoride, the latter being either fluor- 

 spar or cryolite. Both these minerals can be had very cheaply, but Mr. 

 Henry Pemberton, jr., undertakes to show that the difficulties of the 

 process are such as to leave little or no margin for profit. The weak 

 point in the process is the quantity of acid required, and in the produc- 

 tion of three tons of bulky, insoluble, comparatively useless calcium sul- 

 phate for every ton of alum made. Cryolite is shown to be too expen- 

 sive, and moreover yields the wrong alkali, soda in place of potash. 

 And if the necessary potash were added, enormous quantities of Glau- 

 ber's-salt would be left upon the manufacturer's hands. (Journ. Frankl. 

 Inst, 1883.) 



Analyses of the Geyser Waters and Deposits of the Yellowstone National 



Parle. 



Dr. Henry Leffmann has published analyses of the waters of several 

 of the Yellowstone Geysers and of the incrustations forming in their 

 vicinity. From these we select the following : 



I. — Pearl Geyser. 



Grains in imp. gallon. 



Calcium sulphate 1. 40 



• Sodium sulphate 1. 89 



Sodium chloride 61. 39 



SiUca 7. 84 



72.52 



At the bottom of the bottle containing this water impure gelatinous 

 silica was found yielding after drying over strong sulphuric acid : 



Per cent. 



Water 4. 9 



Silica 79. 1 



Alumina traces 



Ferric oxide traces 



Calcium oxide traces 



II. — Opal Spring. 



The water of this spring is opalescent and on evaporation gelatinizes 

 before becoming dry : 



Grains in imp. gallon. 



Sodium chloride 72. 18 



Calcium sulphate 3. 22 



Calcium chloride 4. 06 



Silica 53. 76 



143. 22 



