2 
Mr. W. Gooup LEVISON read the following 
Note on the Production of Ammonia in Nitric Acid Batteries.* 
I first noticed the production of ammonia in a nitric acid 
battery, in the month of January, 1869; and on the 23d of 
that month I showed the phenomenon to Mr. Charles Pearce, 
at Cambridge. It was, however, observed under circum- 
stances that led me for a long time to consider it due to a 
mere local action of the dissolving zinc upon nitric acid 
which had diffused through the porous cup; but recent 
experiments show, to my mind, that this ammonia results 
from a reaction between the electrolytically-liberated hydro- 
gen and the nitrogen of the nitric acid in the inner cup. 
As no discussion of the theory of the battery, to the best 
of my knowledge, takes cognizance of this reaction, I thought 
it might be new and worthy of attention. I must, however, 
confine this note to a mere statement of the fact. 
January 14th, 1873. I put up two small Grove cells, con- 
structed of zine and platinum. The inner cups were filled 
with a mixture of 
Saturated solution of potassic bichromate, . 5 parts, 
Commercial oil of vitriol, : : : a 
Nitric acid, C. P., ; 4 : d ; oe 
The zines, newly amalgamated, were put in dilute sulphuric 
acid. Distilled water only was used. One cup was set in 
operation, the other left. After 24 hours the liquids in these 
two batteries were examined for ammonia; the cup set in 
operation being called Battery A, the other Battery B. In 
testing the liquids from the inner and outer cells of both 
batteries, ten cubic centimeters of each were separately con- 
centrated, by evaporation in a platinum dish, to about one- 
fifth, treated with an excess of caustic soda, and the dish 
covered with a watch-glass having a piece of red litmus paper 
adherent to its under side. 
Battery A. Liquid from inner cup. Paper immediately 
turned blue. Odor of ammonia strongly perceptible. 
Battery A. Liquid from outer cup. Paper became blue 
in a short time. Odor of ammonia very faint. Only a trace 
present. 
Battery B. Liquid from inner cup. Paper faintly 
changed in ten minutes. No odor of ammonia perceptible. 
* This note has been published in the Journal of the Franklin Institute 
for May, 1873, It now appears with some corrections by the author. 
