An exception is made in favor of persons making or using the article for purposes of experiment only.

§ 188. Copyrights.-The copyright laws apply to printing of any kind, pictures, music and statuary, and confer upon the author the exclusive right to make, use or sell copies or the originals. The exclusive right extends to the whole as well as every substantial part of the thing copyrighted, so that, if there is a copy or imitation of any substantial part, it will be an infringement. As to what is a substantial part, the facts in each case must determine. The size of the part taken is not a decisive test, for the true value may be in the small part taken. For purposes of criticism, parts may be quoted, but if the review is a pretense for publishing a substantial copy, it is an infringement.

Whoever infringes the copyright of another is liable, whether it is done innocently or not. general immaterial.

The intent is in

§ 189. Literary property.—The monopoly granted under the copyright statute is enjoyed by the author after publication. Before publication, however, an author has legal rights in the product of his intellect, and these rights were recognized before the copyright statutes.

At common law, so long as an author did not publish his work to the world or abandon it to the public, he retained the right as property to make such use of it as he saw fit. He might, without losing his right, permit others to make a limited use of it. Whoever without the author's consent used his work in whole or part was liable to the author in damages and could be enjoined.

§ 190. Private letters.-Where letters have a literary value the writer has the sole right to publish them,

even though the legal title to the paper is in the recipient. If it is apparent that they were intended for publication, the recipient may also publish them. Any attempt by others to publish them may be restrained by injunction, or damages may be recovered for the publication. So far as a letter has value for historic purposes the recipient may use it. And all papers of every kind may be used. by any one as evidence in any suit, no matter what may be their value.

§ 191. Trade-marks and trade-names.-A trademark is a name, symbol or device used by a person to designate that certain goods or property are made by or used by him only, or that a particular business is conducted by him. The essential quality of a trade-mark is that it is arbitrary in form. If the mark is descriptive of any quality of the goods it is not valid as a trademark. It is intended as a simple and convenient guide to customers. Whoever imitates the trade-mark and so palms off goods under false colors, commits a fraud upon the purchaser, and at the same time causes damages to the owner of the trade-mark, both by the profits he has lost and it may be by the injury to the reputation of his goods. This the law recognizes as a substantial damage, and the trade-mark is regarded as incorporeal property. The law of trade-marks is of comparatively recent origin, although the principles upon which it rests have been long settled as a part of the common law.

The remedy for infringement of trade-marks is practically the same as for infringement of patents, namely, damages for loss of profits, injunction and recovery of the profits made by the infringer.

In the United States recent statutes have been passed authorizing the registry of trade-marks in some cases, and giving them greater value as evidence when registered

than when not. The statutes are generally only declaratory of the common law, and all the remedies that formerly existed are preserved.

Though not a trade-mark technically, a trade-name or sign will receive protection from the courts if it is not merely descriptive and contains no deceptive words or meaning, and a rival may be enjoined from using such name or sign so as to cause injury to the owner. By means of such trade-names what is called the good will of a business is preserved and becomes a valuable property right.

§ 192. Kinds of injuries.-Wrongs that may be done to the owner of personal property through fraud, negligence and nuisance have been considered. There remain to be considered wrongs: (1) By direct force injuring or disturbing the owner in his possession. (2) By conversion or depriving the owner of his property. (3) By neglect to restore to the owner upon demand property to which he is entitled.

§ 193. Trespass by force.-The first class of the wrongs named is known as a trespass by force or vi et armis. By this is intended only a direct injury by the unlawful forcible disturbance of another in his possession of the property. This may amount to a partial or complete destruction of the property. The wrong going only to the possession, it follows that one who has an interest in the property, but has not actual or constructive possession, is not entitled to complain of an injury as a trespass vi et armis, but the injury as to him should be redressed in some other form, as will be seen.

$194. Possession.-The possession referred to

may be (1) that of the general owner, (2) that of one having a special property, as a bailee, mortgagee, etc., or (3) that of one having no title beyond mere peaceable possession. The possession of a servant or agent is in law the possession of the master or principal, and need not be considered as a distinct possession.

Possession need not be actual. If one has the immediate right to possession, he has the general property and is said to have constructive possession. He may maintain an action for trespass against any wrongdoer, except the person who has the special property and actual possession.

Where there is a special property in goods, either the general or special owner may sue a third person for injury to the goods.

One who has mere peaceable possession has sufficient possession to warrant a suit for trespass against any wrongdoer except the owner.

195. The force.-The force used may be by the wrongdoer personally, by his servants or by his animals. It may be either express force, as in robbery, or implied force, as in the act of placing poison before animals. The degree of force is immaterial. To cut a rope tying a cow would be a trespass. It must moreover appear that the injury was proximate.

§ 196. Conversion.-Any distinct act of dominion wrongfully exerted by one person over another's property, in denial of his right, or inconsistent with it, is known as a conversion. It is the denial of the owner's right that distinguishes conversion from trespass, for trespass may sometimes be committed even though the owner's right to property and possession be fully conceded. Whether the act be for the benefit of the wrongdoer or