agent in all its other uses as well as in the particular product he desires. To the enterpriser, cost seems the cause of the value of a product. To the economist it should be clear that the utility found in the various products is the basis of value in the factors, _i. e._, of the costs. [Sidenote: A single source of a single product] 3. _The genealogy of value may thus be traced through the various intermediate products to consumption goods._ A single product having a single source of supply shows most clearly the reflection of value directly from the product. The discovery of a mineral spring or of a good quality of building-stone on worthless land, will cause a value to attach at once to the source of supply. When a great singer like Adelina Patti commands several thousand dollars for each appearance in concert, the source is the magical throat of the singer, and the salary reflects the utility of the music in the minds of delighted hearers. [Sidenote: One source of several products] When the one source of supply yields several different kinds of products there is just one new condition which confuses the thought and suggests the error that value begins in the source (with costs therefore) and not in the product. Looking at the products severally, no one of them explains the value of the source, and, on the contrary, each one is seen to have a value independent of the particular use to which it is put. To make the illustration most simple: a savage finds in a wreck on the coast a number of bars of iron. His fellows wish them for various purposes: to make arrow heads, spears, knives, hatchets, hoes, ornaments, nails, needles, etc. Value is in this case derived in part, through the source, from the alternate uses. Taken jointly and considered as one sum, the value of the various products accounts as completely and exclusively for the value of the source as if they were merged into one product. The source (_S_) is distributed to each of the products in accordance with their marginal utility, and therefore the value of the various products from any source of supply constantly tends to equality. Any unit of product sought for any purpose must be paid for according to a marginal utility determined in all the applications. The genesis of the value is in the utility of the product; the value of the source is derived. [Illustration: _1. A single Product_ _2. Several Products from one Source_] [Sidenote: Complex conditions with intermediate products]