Conversion (also called `Troyer’) consists in wilfully and without any justification dealing with goods in such a manner that another person, who is entitled to immediate use and possession of the same, is deprived of them. It is dealing with the goods in a manner which is inconsistent with the right of the owner. Keeping and refusing to deliver the plaintiff’s goods, putting them to one’s own use or consuming them, destroying them or damaging them in a way that they lose their identity, etc., all amount to conversion.

In Richanison v Atkinson (1723)1 Sum 576, the defendant drew out some wine out of the plaintiff’s cask and mixed water with the remainder to make good the deficiency. He was held liable for the conversion of the whole cask as he had converted part of the contents by taking them away and the remaining part by destroying their identity,

A person dealing with the goods of another person in a wrongful way does so at his own peril and it is no defence that he honestly believed that he has a right to deal with the goods or he had no knowledge of the owner’s right in them. According to Lord Porter, “Conversion consists in an act intentionally done inconsistent with the owner’s right, though the doer may not know of, or intend to challenge, the property or possession of the true owner.”

“If I snatch your hat from your head and throw it at any other person that is trespass to your hat, but it is not conversion, for I am not questioning your title to it. But if I take it from you with intent to steal it, that is conversion as well as trespass” (Winfield). However, a mere taking unaccompanied by an intention to exercise permanent or temporary dominion may be a trespass but is no conversion [Fouldes v Willonghby (1841)8 M & W 501.]

A wrongful sale of goods is conversion. The owner may also recover from the purchaser because the general rule protects interest of the owner as against the buyer, If a warehouseman mis-delivers goods even by mistake he will be liable for conversion [Devereaux v Barclay (1819)2 B & Ald 7021.] The payee of a crossed cheque especially endorsed it to the plaintiffs, a stranger who having obtained possession of the cheque endorsed it in the favour of himself and presented it at the defendants’ bank and thus got it encashed, it was held that the defendants were liable to the plaintiffs in an action for conversion for the amount of the cheque.

The law, however, excuses certain acts, and if they were done in bona fide ignorance of the plaintiff’s title there may be no conversion. The finder of goods is justified in taking steps for their protection and safe custody till he finds the true owner. For an action for conversion, it is also necessary that the plaintiff must’ve a right to the immediate possession of the goods at the time of their conversion. Such an action may be brought by a finder of goods, a bailee or pledgee of the goods, an auctioneer, a person in possession under a hiring agreement, or master of a ship. If the plaintiff cannot prove his right of possession, an action for conversion will fail.

The finder of goods is a ‘person in possession’ (unless he is a trespasser). Thus, in Armory v Delamirie (1721)1 Str 505, the chimney sweeper’s boy, who after finding a jewel had given it to a jeweler to be valued, was held entitled to recover its full value from the jeweler on his refusing to return the same.