4 Mr. Davy’s Lecture on some 
I resumed the enquiry ; I procured small cylindrical cups 
of agate, of the capacity of about | of a cubic inch each. 
They were boiled for some hours in distilled water, and a 
piece of very white and transparent amianthus that had been 
treated in the same way was made to connect them together ; 
they were filled with distilled water, and exposed by means 
of two platina wires to a current of electricity, from 150 pairs 
of plates of copper and zinc 4 inches square, made active by 
means of solution of alum. After 48 hours the process was 
examined : paper tinged with litmus plunged into the tube 
containing the transmitting or positive wire was immediately 
strongly reddened. Paper coloured by turmeric introduced 
into the other tube had its colour much deepened ; the acid 
matter gave a very slight degree of turbidness to solution of 
nitrate of silver. The fluid that affected turmeric retained 
this property after being strongly boiled ; and it appeared 
more vivid as the quantity became reduced by evaporation ; 
carbonate 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 examination could go, 
had the properties of carbonate of soda. I compared it with 
similar minute portions 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 of soda 
soon attracted moisture from a damp atmosphere, and became 
fluid. 
This result was unexpected, but it was far from convincing 
me that the substances which I had obtained were generated . 
In a similar process, with glass tubes, carried on exactly under 
the same circumstances, and for the same time, I obtained a 
quantity of alkali which must have been more than twenty 
