Fig. 263 shows an arrangement suggested by Ungerer for the process of re-percolatien. A number of percolators a b are placed on a suitable stand, one above the other, so that the tube of one percolator passes through a cork fitted into the mouth of the one below: 6 to 12 of these vessels may be used one above the other. The stand consists of a board with pairs of projecting pegs placed at such distances that there is. room for the cylinders between them. Boards having a horseshoe-shaped piece cut out on one tide are placed on these pegs, and serve to support the cylinders in their places. The menstruum is allowed to run into the top cylinder, either freely or (in order to increase the pressure) through a long tube attached to the top. The liquid permeates the substance in the cylinder and runs through into the cylinder below, -and so on to the bottom, where it is drawn off as the strongest possible tincture. By adjusting the lowest stop-cock the speed of flow can be pro* perly regulated. The number of vessels and the speed of percolating should be so regulated that the tincture begins to flow from the lowest cylinder just when the contents of the top one have been thoroughly exhausted.

As soon as the top cylinder is exhausted it is removed, the whole column of vessels is raised up a stage, and a newly-filled vessel is added at the bottom. In this way the process becomes continuous, and a concentrated extract can be made, except, of course, towards the end of the operation.

Egg box.

Egg box.