3 So nearly akin, indeed, is purchase and sale, to letting and hiring, that in some cases it is a question to which class of the two a contract belongs. As an instance may be taken those lands which are delivered over to be enjoyed for ever, upon the terms, that is to say, that so long as the rent is paid to the owner it shall not be lawful for the latter to take the lands away from either the original hirer, or his heir, or any one else to whom he or his heirs has conveyed them by sale, gift, dowry, or in any other way whatsoever. The questionings of the earlier lawyers, some of whom thought this kind of contract a hiring, and others a sale, occasioned the enactment of the statute of Zeno, which determined that this contract of emphyteusis, as it is called, was of a peculiar nature, and should not be included under either hire or sale, but should rest on the terms of the agreement in each particular case: so that if anything were agreed upon between the parties, this should bind them exactly as if it were inherent in the very nature of the contract; while if they did not agree expressly at whose risk the land should be, it should be at that of the owner in case of total destruction, and at that of the tenant, if the injury were merely partial. And these rules we have adopted in our legislation. 4 Again, if a goldsmith agrees to make Titius rings of a certain weight and pattern out of his own gold for, say, ten aurei, it is a question whether the contract is purchase and sale or letting and hiring. Cassius says the material is bought and sold, the labour let and hired; but it is now settled that there is only a purchase and sale. But if Titius provided the gold, and agreed to pay him for his work, the contract is clearly a letting and hiring. 5 The hirer ought to observe all the terms of the contract, and in the absence of express agreement his obligations should be ascertained by reference to what is fair and equitable. Where a man has either given or promised for hire for the use of clothes, silver, or a beast of burden, he is required in his charge of it to show as much care as the most diligent father of a family shows in his own affairs; if he do this, and still accidentally lose it, he will be under no obligation to restore either it or its value. 6 If the hirer dies before the time fixed for the termination of the contract has elapsed, his heir succeeds to his rights and obligations in respect thereof. TITLE XXV. OF PARTNERSHIP A partnership either extends to all the goods of the partners, when the Greeks call it by the special name of 'koinopraxia,' or is confined to a single sort of business, such as the purchase and sale of slaves, oil, wine, or grain.