It will readily be seen that the loss in extraction by such means is very great. In fact, from cane having a sugar content of 15 per cent, sometimes not more than between 5 per cent and 6 per cent of sugar is recovered. The best results are naturally obtained in the large factories, or usines, but even there, owing to poor crushing, 9 per cent of the weight of the cane in sugar is considered satisfactory. In the usines the juices are treated with sulphur and neutralized with lime. They are then allowed to settle, after which they are boiled to grain and the crystals separated from the mother liquor in centrifugal machines. The sugar is dried and the remaining liquor is returned to the pans for reboiling. The various grades produced are: Cristaes blancos (white washed sugar) Cristaes amarellos (first yellow, termed Demerara) Mascavinhos (second yellow, fine grain) Mascavos (dark brown sugar, final product) The greater portion of the sugars made in Brazil is refined, but a certain amount goes directly into consumption in its raw state. Refining on a large scale according to European methods has been tried at various times, but, owing to the high cost of labor, fuel and transportation, all these attempts have proved unsuccessful. Then again, the demand for sugar prepared in the European way is not great, the Brazilians preferring the moist fine-grained sugar made in the small refineries. This sugar has a molasses taste, polarizes about 91 degrees and carries about 2 per cent of glucose. In manufacturing the white grade, a liquor of 31 degrees Baumé[76] is first made from raw sugar. This is clarified with ox-blood and filtered through bone-char, after which the clear liquor is boiled at a temperature of 266 degrees Fahrenheit over an open fire until only about 4 per cent of water remains. It is then removed from the fire, a small quantity of dry granulated sugar is added and the mass is stirred with a wooden paddle. Cool, dry, fine-grained sugar is the result. The yellow grade, or _terzira_, as it is called, is made in exactly the same manner, except that no clarifying or filtering is done. The rich molasses odor and taste of this sugar please the popular palate to such an extent that it commands a higher price than white granulated sugar refined by the most modern processes. In fact nearly 75 per cent of the sugar consumed in Rio de Janeiro is terzira. Its manufacture does not require expensive equipment or any great amount of technical skill, hence it appeals to the native merchants and confectioners.