The object of this invention is to combine in one machine the great requisites which are essential to clean wheat from all foreign 8ubstances before grinding, namely, a capability of separating all lighter foreign substances by blast ; separating by screening all such foreigu material that will not pass off hy the blast ; depriving the grain of all smut which may not have been blown off before arriving at the scouring cylinder, and lastly, depriving the wheat by a light suction, of dust, as fast as it passes from the scouring cylin- der, without lifting and interfering with its discharge. How these points are attained will be seen by tM following description, reference being made to the illustration, which is a vertical longitudinal section of the invention. A is the frame of the machine, and B is the scouring chamber, supported by the cross-pieces, a a. This. chamber is formed of a series of chambers matched together as seen at b, and the castings are of such a shape as is indicated by f e d, the surface of e being plain, while that of f is fluted to correspond with the flutings, g, on the conical scouring plates, j, that revolve within the chambers, d e f, by being supported on and attached to the central vertical shaft, C. The chambers and scouring platcs are encased by an outer cylinder, D. By thus forming the scouring plates conical, and the chambers to match, the grain is subjected to a very large scouring surface, retarded in its progress, and its gravity still made available to assist in its escape as fast as acted upon. is the fan cylinder, within which the fan, E', arranged on the shaft, C, rotates. The fan casc terminates in a horizontal blast spout, F, whid, gradually flares laterally as it reaches its discharge end. F' are two valves at the bottom of the fan case for admitting more or less air to the fan, accordingly as it is desired to have the strength of the blast. G is the vertical spout for separating the various qualities of screenings from one another; it is placed in the end of the blast spout, and is closed at top, but open to a certain extent on the other sides ; its lower end is dividetl into three passages, 1 m n, by means of partitions, oo. HI are two sliding screw gates formed partly of wire gauze, aRd they are made adjustable, and serve for separating the different qualities of screenings from one another, as soon as the wheat is separated therefrom, and by having them adjustable they can be regulated in hight to suit the specific gravity of different kinds of wl,eat. J is the shoe which receives tIle wheat _as it falls through the blast from the wire guazo chute, K, of the hopper, L. This shoe is formed of two inclines, r 8, r being of wire gauze and hinged at u, and capnble of adjustment by a set screw, and the other incline, I, allowing the cockle that falls through r to pass into the spout, G. The advantage of having this incline adjustable is that it can be made more or less inclined to suit the amount of cockle in the wheat, the greater quantity of cockle requiring a less incline in order that the wheat may remain longer in contact with the incline, so as to separate the whole of it. Another advantage is, that, the shoe itself does not require adjusting, and consequently the space between the fan case and the scouring chamber does not require to be great, in order to allow for adjustment. The vibration of the shoe is effected by means of a cam, t', on the driving ahaft, this projection striking the rod, v', in the revolution of the shaft. M is a suction spout, leadin-g up from near the bottom of the frame to the fan case, and communicating with the scouring chamber by a passage, N, and with the fan chamber by a passage, N'. In the opening, N', is a valve which regulates the draft through the spout, and thus avoids the lifting up of the grain through the spout by too great snction. At the bottom of the spout, there is, as usual, an inclined wire gauze screen or chute for the grain to pass over in its discharge, and so be deprived ot its dust just before leaving the machine. This most perfect smut machine is the invention of Daniel M. Donehoo, of Hookstown, Pa., wio will be hacpy to furnish any further particulars of the machine or other business. It was patented March 16, 1858. AGRicUltUral ExhiRition.The Agricultural Association of Upper Canada holds its annual exhibition at Toronto on the four days included between Sept. 28 and. Oct. 1. On the list of prizes which we have received, there is this remark, "Open to all Canada." 1 Why not be liberal, and open your prize list to all America?