412 Mr. J. A. Phillips on the Origin of Mineral Veins. 



Water from the Irish Water from Botallack 

 Sea so diluted with taken from workings 

 distilled water as to under the sea, 



contain 14*3047 grammes " Crown Mine." 

 solid matter per litre. 



( 



Grammes per litre, 



Grammes per litre, 





calculated. 



found. 



Chlorine . . 



. 7-8734 



6-2778 



Iodine . 



• 3) 



trace 



Bromine 



. -0259 



trace 



Sulphuric acid 



. 1*0959 



1-2129 



Silica . . 



)> 



trace 



Alumina . . 



}> 



. -0064 



Lime 



. -2431 



1-9970 



Magnesia . . 



. -8590 



•2182 



Ferric oxide 



. -0019 



•0143 



Alkaline chloride* 



3. 11-4905 



9-7556 



Potassium . . 



. -1654 



•1392 



Lithium . 



trace 



•0119 



Sodium 



4-3969 



3-7054 



Ammonia . . . 



trace 



not estimated 



Carbonic acid 



•0096 



2-2114 



Nitric acid . . 



•0006 



not estimated 



In the above Table a general accordance will be observed be- 

 tween the figures obtained by analysis of the Botallack water 

 and those calculated on an assumed mixture of sea-water with 

 distilled water; it will be remarked, however, that lithium and 

 large quantities of lime and carbonic acid have been taken up. 

 A comparison of the figures in the two columns also renders 

 it evident that magnesia has been in some way abstracted from 

 solution, although the rocks in which the lode is enclosed have 

 been found to contain much larger quantities of magnesia than 

 of lime*. 



Copper, zinc, lead, tin, &c. were carefully sought for by the 

 usual tests without success ; but the spectroscope was only em- 

 ployed for examining the alkaline chlorides with the flame of 

 an ordinary Bunsen gas-burner. It is, however, probable that 

 traces of various substances, present in such minute quantities 

 as to escape detection by ordinary means, might be found by 

 spectroscopic observation with the assistance of a powerful in- 

 duction-coil ; and I therefore propose to make further investiga- 

 tions by the aid of this instrument, and also to operate on very 

 large quantities of the various waters subjected to analysis. 



* Analyses of two of the clay- slates from this locality afforded respec- 

 tively: — lime 405, magnesia 6"58 per cent. ; and lime 4'/8, magnesia 11 61 

 per cent. Phil. Mag. February 1871. 



