As you have already read in a previous chapter that corks are cut vertical parallel, or, to state more clearly, the axis of the stopper must be parallel with the axis of the tree that furnished the bark; and the desired direction is easily recognizable by the colored striae due to the annual layers of suberous substance that are observed in the direction of its axis, this rule being followed because cork is found to be more impervious to liquids if cut in this manner. It will be readily seen that if disks are cut horizontally parallel, that is, the annual layers running at right angles to the axis of the disk, this grade of cork can be utilized to great advantage. The mode of cutting is by a horizontal revolving blade, which slices the cork to the desired thickness, usually a quarter of an inch, and then it follows the usual course of punching, etc. From these operations a great deal of waste accumulates, and this would be a great loss if methods were not devised for its utilization. Many firms work up this waste on the premises, but most of it is shipped out and its conversion forms a separate part of the corkwood industry, which will be described later. We might say now that the cork is made, for it has been cut and shaped into the desired commercial size; and all that remains is to sort them and ship them away. But if commerce desires sizes and quality, it has also exacted many other requirements of a cork before it is acceptable and we will now take up the further manipulation of cork before it leaves the factory. Naturally, this corkwood, coming such a distance and being handled by so many in the general processes just described, gets more or less dirty, and aside from that perhaps in the growing the tissue has not remained as white as is desired, so before the cork can leave the factory it has to be washed or cleaned. And in this washing I will not say that there is not an attempt to improve the looks of the corks in order to get a better price. Now this washing or bleaching is carried on in the simplest manner and is just soaking the corks in water and a chemical and then placing them in a centrifugal spinner, which is nothing more than a perforated receptacle made to revolve within an iron jacket, which is connected to a drain, naturally forcing the material against the periphery and thereby causing the excess water and acid to pass out through the perforations, this system becoming quite common in cork factories to-day, greatly facilitating the drying, which is done mostly by the atmosphere. This is all there is to the mechanical part, but curiosity prompts us to inquire what chemicals are used to clean the corks, so I have ascertained the principal ones, but of course every manufacturer will have his own way of doing this part of the work, although the principle remains the same. An old way was to wash them in water containing chloride of tin or oxalic acid and then subjecting them