THE FARMER AT HOME. 303 



mended in haemorrhages, alvine fluxes, and other preternatural or 

 immoderate secretions ; and in these it is sometimes attended with 

 good effects. Some have alleged that by the use of this bark every 

 purpose can be answered which may be obtained from Peruvian bark. 

 But, after several very fair trials, this is found not to be the case. Be- 

 sides the bark, the buds, the acorns, and their cups are used ; as also 

 the galls, which are excrescences, caused by insects, on the oaks of 

 the eastern countries, of which there are divers sorts ; some perfectly 

 round and smooth, some rougher with small protuberances, but all 

 generally having a round hole in them. 



OAR. A long piece of timber, flat at one end, and "round or 

 square at the other, used to make a vessel advance upon the water 

 The flat part, which is dipped into the water, is called the blade, and 

 that which is within the board is termed the loom, whose extremity, 

 being small enough to be grasped by the rowers, is called the handle. 

 To push the boat or vessel forwards by means of this instrument, the 

 rowers turn their backs forwards, and, dipping the blade of the oar in 

 the water, pull the handle forward, so that the blade, at the same 

 time, may move aft in the water. But since the blade cannot be so 

 moved without striking the water, this impulsion is the same as if 

 the water were to strike the blade from the stern towards the head ; the 

 vessel is therefore necessarily moved according to the direction. Hence 

 it follows, that she will advance with greater rapidity, by as much as 

 the oar strikes the water more forcibly ; consequently, an oar acts up- 

 on the side of a boat or vessel like a lever of the second class, whose 

 fulcrum is the station upon which the oar rests on the boat's gun- 

 wale. 



OATS. The great use of oats, and the ease with which they are 

 raised on almost every kind of soil, from the heaviest loam to the 

 lightest sand, have made them occupy a place in almost every rota- 

 tion of crops. It is said that the best oats are raised in Scotland and 

 Friesland. The average yield on good soils is from thirty to forty 

 bushels per acre, and on the richest soils when well cultivated, the 

 produce has been over one hundred bushels to the acre. The oat is 

 exposed to fewer injuries than other grain, being seldom affected by 

 rust, smut, or insects. It succeeds best in cold and moist countries. 

 The meal is nutritious, and, in some countries, forms an important 

 article of food, for instance in Ireland particularly ; but the bread 

 made of it is rather indifferent in quality, and somewhat bitter. Beer 

 is made from this grain in Britain and Poland ; and it is besides dis- 

 tilled to procure ardent spirits. Oats are the best food for horses, and 

 for this purpose, in our own country, are principally cultivated. 



OIL STONE. In Natural History, is a stone of a whitish color, 

 with a faint mixture of a bluish grey ; and it is sometimes ornament- 

 ed with black spots and dendrita3. It is of a moderately fine and 

 compact texture, hard and heavy, and capable of a tolerable polish. 



