It may be pointed out, on the other hand, that the “gains,” both in industry and commerce, are far in excess of those of agriculture. All this was immaterial to the Physiocrats, for “they were gained, not produced.”[31] Such gains simply represented wealth transferred from the agricultural to the industrial classes.[32] The agricultural classes furnished the artisans not only with raw material, but also with the necessaries of life. The artisans were simply the domestic servants, or, to use Turgot’s phrase, the hirelings of the agriculturists.[33] Strictly speaking, the latter could keep the whole net product to themselves, but finding it more convenient they entrust the making of their clothes, the erection of their houses, and the production of their implements to the artisans, giving them a portion of the net product as remuneration.[34] It is possible, of course, that, like many servants in fine houses, the latter manage to make a very good living at their masters’ expense. The “sterile classes” in Physiocratic parlance simply signifies those who draw their incomes second-hand. The Physiocrats had the good sense to try to give an explanation of this unfortunate term, which threatened to discredit their system altogether, and which it seemed unfair to apply to a whole class that had done more than any other towards enriching the nation. It is a debatable point whether the Physiocrats attributed this virtue of furnishing a net product solely to agriculture or whether they intended it to apply to extractive industries, such as mining and fishing. They seem to apply it in a general way to mines, but the references are rare and not infrequently contradictory. We can understand their hesitating, for, on the one hand, mines undoubtedly give us new wealth in the form of raw materials, just as the land or sea does; on the other hand, the fruits of the earth and the treasures of the deep are not so easily exhausted as mines. Turgot put it excellently when he said, “The land produces fruit annually, but a mine produces no fruit. The mine itself is the garnered fruit,” and he concludes that mines, like industrial undertakings, give no net product, that if any one had any claim to that product it would be the owner of the soil, but that in any case the surplus would be almost insignificant.[35]