The general rule is that "fixtures are any chattels which have become substantially and permanently annexed to the land or to buildings or other things which are clearly a part of the land."[D] The annexation may, however, be purely theoretical, since the keys to the house or barn, which may be in the owner's pocket, are real estate. One rule concerning fixtures is that they must be so annexed that they cannot be severed without injuring the freehold. The intention of the party making the annexation also often determines, since if the article is annexed with the intention of making it permanent, it then becomes a part of the land. Among the things held to be fixtures, and therefore a part of the land, are: (1) All buildings and everything which is a part of any building, such as doors, blinds, keys, etc.; (2) fence materials which have been once used and are piled up to be used again are a part of the land, but new fence material not yet used is personal property. (3) Growing crops are real property. They go to the purchaser of the land unless specially reserved in the deed. A verbal agreement is not sufficient. (4) Trees, if blown down or cut down and still lying where they fell, are real property; if cut or corded up for sale they become personal property. (5) All manure made on the farm is real estate and passes with the land. (6) All the ordinary portable machines and tools are considered personal property, but certain machines held to be of permanent use upon the land are real estate. Among the things which courts have held to go with the land are cotton gins, copper kettles encased in brick and mortar for cooking food for hogs, cider mills, pumps, water pipes bringing water from distant springs. In general, motive power machinery and the shafting go with the land, but the machinery impelled may or may not, depending upon the way it is annexed. (7) If stones have been quarried for the purpose of using upon the farm, they go with the farm, but if quarried for sale they are personal property. CONTRACTS The difference between personal property and real property may be indicated by considering the essential features of a contract. A contract is an agreement between two or more persons. The foundation rule concerning a contract is that every man must fulfill every agreement he makes. An ethical practice grows out of this legal rule which, if strictly adhered to, will save much embarrassment, viz., make but few promises and always keep your engagements.