1868 The complete Practical Distiller

175

SPECIAL DISTILLATIONS.

The steam-boiler should be supplied constantly with water, and it must be perceived that in consequence of this exigence this system would require, in each operation, the combustibles necessary to boil the water requisite for the distillation of the lees ; these lees are rendered poorer when heated, for vapour of water which fills this function can only produce this effect through its condensation in the mass, by uniting with it until the ebullition com- mences, when this vapour determines the analysis. It is true that with three stills the expenses would not be so considerable ; but evidently they would always be supplementary to those which are attached to the distilla* tion of fluid wines by the same process. This mode of distillation is thus recommended to those it concerns, if it were only to deprive the pressed lees, obtained by the means that will be indicated, from the alcohol which they retain after the operation of pressing. If more complicated apparatus were made use of for the purpose of distilling lees, such, for instance, which, like the continuous apparatus, force the wine through nume- rous circulations before it arrives to ebullition, it would be difficult, not to say impossible, to obtain good results; the solid substances would keep in the angles of the ap- paratus, obstruct the conduits, and present a vast number of similar difficulties, which experience gives us no hope of removing. The other mode which has been proposed for the distillation of lees is this : — It consists in assimi- lating these wines to those that are perfectly fluid, by first separating by precipitation all the liquid they con- tain, and by submitting the solid residues to the action of an energetic press.