machine a 39 is joined directly to the grinding vessel 33 of the stirrer mill b 39 the grinding vessel 33 is provided with a double jacket 34 having an inlet aperture 35 and an outlet aperture 36 for a cooling or heating liquid the stirrer shaft 37 with stirring discs 38 and a mounting 39 rotates in the grinding vessel 33 in the presence of the grinding elements 40 here again the shape of the stirring discs 38 and the type quantity and size of the grinding elements 40 correspond to the material being mixed and ground in each particular case at the upper end of the grinding vessel 33 a separating device 41 which is here shown as a cylindrical sieve serves to separate the grinding elements 40 from the ground material the latter leaves the stirrer mill b 39 via an outlet 42 for the continuous metering of the solid component use is made of a metering device 43 shown here while the dispersion medium which is for example in liquid form is fed to the worm machine by way of a pipe 45 by a metering pump 44 another component for example in liquid form is fed to the worm machine a 39 by means of a metering pump 46 by way of a corresponding pipe 47 in the second half of the length of the worm in cases where the material to be treated consists of a plurality of solid components or of dispersion medium components metering must naturally be effected for each component it is however also entirely possible for solid components having similar metering properties to be previously grouped together or premixed and conjointly fed by.