The blanket table, too, gives place at the modern mine to the "vanner," of which there are several varieties. Essentially they are much the same, and a description of two will serve to give an idea of them all. Let us take the "Record" vanner. Imagine a large table formed of wood, the upper surface covered with linoleum. It is fixed on slides so that it can move to and fro endwise. It is given a slight slope in the direction at right angles to its length--that is to say, one edge is a little lower than the other. The material is fed on at one end, at the higher edge, and naturally tends to run down and off at the lower edge. It is restrained somewhat from doing this by the presence of rows of riffles or ridges running lengthwise. Nevertheless it does in a short time find its way off the table at the lower end. But all the time that it is at work the table is being slidden backwards and forwards on the slides. By a simple but curious mechanism it is arranged so that it moves quickly in one direction and slowly in the other, with the result that the heavier particles of sand--those which contain gold--are carried to the farther end of the table. Thus, as has been said, all the stuff is fed on to the higher edge and carried down by the water, until it falls off at the lower edge, but during the journey from edge to edge the peculiar motion of the table causes the different kinds of sand to separate themselves, so that the concentrates fall off near one end, and the rest near the other end. Another interesting example of ingenuity is the well-known "Frue" vanner. In this the table is a broad, endless band of india-rubber, extended upon two rollers, one of which is slightly higher than the other. The stream of water and crushed ore flows on at the upper end, and runs down to the lower, the lighter particles being carried down and dropped off at the _lower_ end, while the heavier rest upon the band. Meanwhile the turning of the rollers carries the band slowly along, so that the heavier particles gradually ascend and are carried over at the _upper_ end. To assist in the separation, the whole concern is given a side-to-side shaking motion while it is at work. We have seen so far how the ore is crushed, and the coarser grains of gold got out of it by the aid of mercury. The mixture of mercury and gold is termed amalgam, and the process of extracting gold by mercury is called amalgamation. The gold is actually dissolved in the mercury, and so when the amalgam has been (as it is periodically) collected from the plant, it has to be filtered and then evaporated in a retort. The mercury vapour is caught and condensed back into a liquid, while the gold is left in the retort. In fact the amalgam is distilled in order to separate the gold and mercury.