The rise in prices which began about 1896 and which was accelerated by the Great War naturally turned the attention of both producers and consumers to the question of substitutes. The result has been that many goods have been compelled to compete with substitutes. At times the battle between the two has become intense. Butter and oleomargarine, for example, have contested for supremacy, the producers of each basing their claims for preference on uniformity in texture, cleanliness, and nutrition. In support of what was said in the preceding paragraph, the fact may be cited that tons of the latter have been consumed by hotel and restaurant patrons who, if they were questioned in the matter, would have declared their inability to eat any substitute for butter. Substitutes have been found for many other foods, such as wheat bread, olive oil, maple sirup, and eggs. Likewise, substitutes for numerous other kinds of goods have been discovered, until one scarcely knows just when he is buying leather, silk, cloth, furs, paints, or oils.