(153.) Although the cost of any article may be reduced in its ultimate analysis to the quantity of labour by which it was produced; yet it is usual, in a certain state of the manufacture of most substances, to call them by the term raw material. Thus iron, when reduced from the ore and rendered malleable, is in a state of preparation for a multitude of useful purposes, and is the raw material out of which most of our tools are made. In this stage of its manufacture, but a moderate quantity of labour has been expended on the substance; and it becomes an interesting subject to trace the various proportions in which raw material, in this sense of the term, and labour unite to constitute the value of many of the productions of the arts.

(154.) Gold-leaf consists of a portion of the metal beaten out to so great a degree of thinness, as to allow a greenish-blue light to be transmitted through its pores. About 400 square inches of this are sold, in the form of a small book containing 25 leaves of gold, for 1s. 6d. In this case, the raw material, or gold, is worth rather less than two-thirds of the manufactured article. In the case of silver-leaf, the labour considerably exceeds the value of the material. A book of fifty leaves, covering above 1,000 square inches, is sold for 1s. 3d.