A HISTORY OF SCIENCE 



kali, the materials employed for the manufacture of 

 tobacco-pipes are not at all such as to exclude the com- 

 binations of this substance. 



" I resumed the inquiry; I procured small cylindrical 

 cups of agate of the capacity of about one-quarter of a 

 cubic inch each. They were boiled for some hours in 

 distilled water, and a piece of very white and trans- 

 parent amianthus that had been treated in the same 

 way was made then to connect together; they were 

 filled with distilled water and exposed by means of two 

 platina wires to a current of electricity, from one hun- 

 dred and fifty pairs of plates of copper and zinc four 

 inches square, made active by means of solution of 

 alum. After forty-eight hours the process was ex- 

 amined: Paper tinged with litmus plunged into the 

 tube containing the transmitting or positive wire was 

 immediately strongly reddened. Paper colored by 

 turmeric introduced into the other tube had its color 

 much deepened ; the acid matter gave a very slight de- 

 gree of turgidness to solution of nitrate of soda. The 

 fluid that affected turmeric retained this property 

 after being strongly boiled ; and it appeared more vivid 

 as the quantity became reduced by evaporation; car- 

 bonate of ammonia was mixed with it, and the whole 

 dried and exposed to a strong heat ; a minute quantity 

 of white matter remained, which, as far as my exam- 

 inations could go, had the properties of carbonate of 

 soda. I compared it with similar minute portions of 

 the pure carbonates of potash, and similar minute por- 

 tions of the pure carbonates of potash and soda. It 

 was not so deliquescent as the former of these bodies, 

 and it formed a salt with nitric acid, which, like nitrate 



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