H 
Mr . Davy’s Lecture on some 
V. On the Passage of Acids, Alkalies, and other Substances 
through various attracting chemical Menstrua , by Means of 
Electricity. 
As acid and alkaline substances during the time of their 
electrical transfer passed through water containing vegetable 
colours without affecting them, or apparently combining with 
them, it immediately became an object of enquiry, whether 
they would not likewise pass through chemical menstrua, 
having stronger attractions for them ; and it seemed reason- 
able to suppose, that the same power which destroyed elective 
affinity in the vicinity of the metallic points, would likewise 
destroy it, or suspend its operation, throughout the whole of 
the circuit. 
An arrangement was made, of the same vessels and appa- 
ratus employed in the experiment on the solution of muriate 
of soda and sulphate of silver, page 23. Solution of sulphate 
of potash was placed in contact with the negatively electrified 
point, pure water was placed in contact with the positively 
electrified point, and a weak solution of ammonia was made 
the middle link of the conducting chain ; so that no sulphuric 
acid could pass to the positive point in the distilled water, 
without passing through the solution of ammonia. 
The power of 150 was used : in less than five minutes it 
was found, by means of litmus paper, that acid was collecting 
round the positive point ; in half an hour, the result was suf- 
ficiently distinct for accurate examination. 
The water was sour to the taste, and precipitated solution 
of nitrate of barytes. 
Similar experiments were made with solution of lime ; and 
