dz d%z In all these equations let x = 0; then z = a0) ^ = au = °3' <Pz -t-t= as,...; and y = /(ao); in whatever manner therefore the flu. dy d^y values of ~, , ... given in (155), (156), (157), ... are composed of f(z),f\z), f"{z),... combined with ^, ~, — i in the same manner will these values, when x = 0, be composed of f(tio), /'(ao)> / "(flo), • • • combined with a1.O2.a3> • • • • From this peculiarity we may deduce the following process; is the differential of /(oo) on the supposition that dao = ax; [^jQ is the second differential of /(ao) on the supposition that da<> = au [dnv~\ supposition that da0 = al5 o"ai = a%, da2 = a3,... dan_i = a„. In |