Traber (Nervus Opticks, 1675), but their accounts are generally more interesting theoretically than as recording progress in the practical use and development of the instrument.
So accurate and convenient is this determination that it is now used conversely as a practical definition of the ampere, which (defined theoretically in terms of magnetic force) is defined practically as the current which in one second deposits i '18 milligramme of silver.
The logarithmic formulae for these concentration cells indicate that theoretically their electromotive force can be increased to any extent by diminishing without limit the concentration of the more dilute solution, log c i /c 2 then becoming very great.
When the series is theoretically continuous, the theoretical graph will be a continuous figure of which the lines actually drawn are ordinates.
These subdivisions of the larger groups are not necessarily those theoretically approved by the present writer, but they have the valuable sanction of the individual experts who have given special attention to different of the vast field represented by the animal kingdom.'