41 
amalgamated was placed within the cell, — in the first 
instance the zinc weighed 114 grains. 
At 8h. 27m. the galvanometer balanced 57 grains. 
5? 
35 
ditto 
54 
>> 
>> 
40 
ditto 
58 
» 
>> 
50 
ditto 
57 
5) 
57 
ditto 
57 
5)283 
56.6 
The zinc then weighed 83 grains, 31 having been dis- 
solved ; thus the instrument, instead of having balanced 
62 grains on the average, had only balanced 56.6, and, 
therefore, required adjusting, either by altering the position 
of the magnet, or altering the length of the arms of the 
balance, which for this purpose are conveniently made of 
two thin slips of brass, each cemented with shell lac on 
thin pieces of wood, the pieces of wood being also cemented 
to the coil; thus the small brass arm being warmed in the 
flame of a lamp, the length of the arm from the pivot is 
easily altered, without affecting the wrapping of the coil. 
The indications of the coil of 100 feet of small wire may, 
in like manner, be adjusted to a standard, by making the 
arms of the balance support 16 grains, by the electromotive 
force of a single pair of elements; of zinc in diluted sul- 
phuric acid 1 to 10, and of platina in nitric acid; the results 
should then be nearly comparable with a table of intensities 
of various combinations, published by Mr. Joule in the 
Philosophical Journal. The observations thus obtained may 
also be reduced by multiplying the number of grains sup- 
ported by such constant number; that in the case of the 
elements selected for a standard, the product divided by 
the resistances of the combination of metal porous cell and 
electrolites, plus the resistances of the galvanometer and 
connecting wires, may agree with the weight supported by 
