1889.] Deposits of Barium Sulphate from Mine-water. 369 



Bedson and Lebour have kindly furnished me with sections for 

 chemical examination. The following results were yielded by the 

 analyses : — 





Harton, 

 box-deposit. 



Jane Pit, 

 Walker- 

 deposit. 



Newsnam, 

 box-deposit. 





0-83 



0-26 



0-39 





2 15 



1 51 



1 95 



Fe 2 3 + A1 2 3 . . 



5 -44 



12 



0-37 



BaO.... 



56-72 



61-30 



61 09 



SrO 



trace 



0-35 



09 





109 



70 



0-82 



MgO 



0-12 



14 



trace 



S0 3 



31-10 



33 -80 



32-82 





1-19 



53 



22 



Alkalis, &c. (by difference) 



1-36 



1 29 



2-25 





86-37 



93-35 



93-03 



The above deposits were mainly buff-coloured with thin layers of 

 brown interposed; they were soft and loose, powder being easily 

 detached by rubbing the surface with the finger. There was no 

 appearance of crystallisation, but every indication of the deposit 

 having been formed by rapid precipitation. 



Professor Bedson (' Journ. Soc. Chem. Industry,' vol. 6, p. 712) and 

 others have found barium chloride to be a common constituent of 

 colliery waters of the district in which the above deposits have been 

 formed. Relatively large quantities of the chloride have been found 

 in some of these samples. The deposition may possibly arise from 

 the admixture with such water of water containing sulphuric acid or 

 ferrous sulphate, or both ; since these substances are constantly 

 formed by the oxidation of pyrites in the coal or in the associated 

 shale beds. Or the barium sulphate occurring in veins in the coal 

 measures may pass into solution under conditions yet unknown, and 

 be deposited again as such. 



Bischof mentions that hot springs may contain BaC0 3 and Na 2 S0 4 

 together in solution ; since at high temperatures these substances do 

 not undergo double decomposition. Such a spring water will, however, 

 deposit BaS0 4 as it cools; since at ordinary atmospheric temperatures 

 BaS0 4 and Na 2 C0 3 are produced by the interchange of constituents. 

 Possibly alteration of temperature may in a similar manner give rise 

 to the above remarkable water-box and pipe deposits. 



Possibly the deposition of barium sulphate in the form of stalactite, 

 which has occurred in some parts of Derbyshire, may be due to the 

 same causes as these mine- water incr ustations. 



2 ,1 ?. 



