Mr. Henry C. Brush, of Brush's Mills, N.Y., has patented through the Scientific American Patent Agency an improved troller, the novel feature in which consists in attaching a float to the shank of the implement under the revolving blade, the object being to keep the troller near the surface of the water, where the fish may see it more readily, and whereby the liability of catching in weeds and logs is obviated. [Illustration] A is a float, attached to the shank, _a_, of the troller. B is the spoon, which is swiveled in the usual manner. The device is very simple, and is claimed to prevent all the annoyance arising from the hook catching in sunken obstructions. * * * * * PURIFICATION OF WOOL AND WOOLEN STUFF. The process, patented some time ago, for the removal of straw, burrs, etc., from wool, by treatment with sulphuric acid, has been modified by Lisc as follows: The stuff is worked for one to two hours in a bath consisting of about 26 gallons sulphuric acid, of 3 deg. to 6 deg., 1 lb. alum, 1/2 lb. salt, and 750 grains borax. It is then treated in a centrifugal machine, and afterward subjected to a temperature of 212 deg. to 248 deg.. For removal of the acid it is first washed with pure water for 11/2 hours, then treated for two hours with fuller's earth, soda, and lime, and finally washed for two hours with fresh water. As sulphuric acid can only be employed with uncolored cloths, or such as have been dyed with indigo, chloride of zinc and chloride of manganese diluted to 6 deg. are substituted with fabrics otherwise dyed. * * * * * CAFFEONE. Caffeone, the aromatic principle of coffee, may be isolated by distilling 5 or 6 lbs. roasted coffee with water, agitating the aqueous distillate with ether, and afterwards evaporating the ether. It is a brown oil, heavier than water, in which it is only very slightly soluble. An almost imponderable quantity of this essential oil will suffice to aromatize a gallon of water. * * * * * THE HEMI-PLUNGER.