dupont's ARTESIAN WELL AT LOUISVILLE. 197 



for a sulphate; should this be present it must be got rid of by 

 exact neutralization with chloride of barium (a slight excess 

 of the chloride of barium will not interfere with the other steps 

 in the analysis). In the examination of the water in question 

 no trace of sulphate was found at this stage of the process; so 

 it was again evaporated to dryness in a small capsule over a 

 water-bath; there were now a few grains of residual matter. 

 To this was added an ounce of a mixture of equal parts of pure 

 ether and absolute alcohol, the capsule was covered with a small 

 receiver and allowed to stand for eighteen hours, the liquid was 

 then thrown on a small filter, and the filter washed with a little 

 of the mixture of ether and alcohol. The alcoholic ether solu- 

 tion, evaporated to dryness, furnished the chloride of lithium, 

 recognized by its well-known characteristics. Although this 

 process requires considerable time and some careful manipu- 

 lation, its results are both accurate and satisfactory. The 

 evaporation of two hundred gallons of the water, and the 

 examination of the concentrated mother-w T ater, enabled me to 

 detect rubidium and caesium by the aid of the spectroscope. 



The water of this artesian well has very valuable medical 

 properties, and those readers who are curious to examine into 

 these points will obtain all the required information by sending 

 to Louisville for the medical report. 



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