This method makes it specially possible to overcome the chromatic and spherical aberrations of higher orders and to fulfil – the sine-condition, and the chief merit of this improvement belongs to Amici.
For this reason Amici constructed objectives of a similar aperture and focus for different thicknesses of glass covers.
C. par Theodore Parrhase (Amsterdam, 1699); and Vita et opera ad annum Mdccxi., amici ejus opusculum, philosophicis Clerici operibus subjiciendum, also attributed to himself.
This method makes it specially possible to overcome the chromatic and spherical aberrations of higher orders and to fulfil - the sine-condition, and the chief merit of this improvement belongs to Amici.
Amici was likewise the first to produce practical and good immersion-systems. The slight difference of the refractive indexes of the glass cover and the immersion-liquid involves a diminution of the aberrations, by which the objective will become less sensitive to the differences in thickness of the glass covers and admits of a more perfect adjustment.