There is something about riding in a cab that causes people to lose things.

When it is time to pay the fare, the passenger goes into a routine that looks like a scene from a Marx Brothers comedy.

A glove comes off, a wallet comes out, the glove is transferred to the other hand as eyeglasses go on, a briefcase is clutched between the knees, the other glove comes off and is dropped, picked up, and held between the teeth as the first glove is placed in the pocket into which the eyeglasses are supposed to go, and pretty soon the poor passenger doesn't know whether he's paying his fare or getting a haircut.

Let me tell you about two reports that came to my desk this week. The first was from a woman who lives at the Watergate, where Diamond has the cab concession. After a cab trip, the woman discovered that one of her gloves was missing, so she called Diamond and was shocked to learn that the company no longer maintains a lost-and-found department.

Later she was thrilled to encounter the same cab driver and to learn that he had found her glove and had been watching for an opportunity to return it to her. Nevertheless, she though I ought to find out why Diamond maintains no lost-and-found department.

The second report is from a gentle soul named Henry Mitchell who writes for our Style Department. After a Diamond Cab delivered Henry to The Washington Post, he discovered that his wallet was missing. He retraced his steps to the point at which he had gotten out of the cab, but there was no sign of the wallet.

Henry tried to call Diamond, but it was a busy day for taxicabs and he couldn't get through. Very frustrating.

While Henry was still dialing, Diamond driver James Loefler Jr, arrived on the scene. His next passengers had been three men who found Henry's wallet on the floor of the cab and turned it over to Loefler.

Like the woman who got back her lost glove. Henry was ecstatic. His money was safe. His credit cards and his professional ID were safe. And, most important of all for somebody like Henry Mitchell, fate had brought him together with four strangers who turned out to be honest and decent people - just the right kind of men to bear out the Mitchell thesis that this is a wonderful world because almost everybody in it is honest and decent.

Now let's take a look at the practical aspects of these two cases. Neither the woman who lost the glove nor the man who lost the wallet figured to learn much by calling Diamond. Both would have been better advised to call the Public Vehicles Division of the D.C. Department of Transportation. It informal name among cab drivers is "the Hack Office."

Maurice J. Harmon of the Hack Office tells me that under our recently revised laws, a hacker who finds property inadvertently left in his vehicle must report it at once - not to his company's lost-and-found office but to the District's Hack Office. Losers also call the Hack Office to report losses. When matchups are made and the loser can satisfy Harmon that he's the rightful owner, the property is restored to him.

No need to clip and save this item. If you ever have need to call Harmon and have forgotten the formal name of his office, don't worry about it. The phone book listing is easy to find. Look under District of Columbia Government, then under Transportation Dept. You'll find a line there that says. "Taxicab Complains Lost & Found & Rates, 347-1398."