The map instructed the "drug dealer" to drive to the Hilton Hotel in Wilmington, Del. It said that behind the hotel, under a bush near the creek and a 25-foot willow tree, he would find the drugs.

When the dealer went to the site Nov. 20, he found two ammunition boxes containing an ounce of a narcotic drug 1,000 times more powerful than heroin, another ounce of a similar substance and two ounces of amphetamines. Continuing to follow instructions, on Dec. 1 the dealer put $40,000 in cash in the two boxes. Following another map, at exactly 7 a.m. he placed the money in a newly dug hole just off a path near a Wilmington middle school.

That night, according to federal agents, the money was picked up by Michael C. Hovey, a research chemist for E.I. du Pont de Nemours & Co. The "dealer" who picked up the drugs was William R. Bouldin, an agent of the Drug Enforcement Administration.

DEA agents said Hovey was producing the drug during working hours in his Du Pont laboratory, using requisitioned Du Pont chemicals. William Glanz, agent in charge of the Wilmington DEA office, said it is the first case in which a large commercial lab was used for major illegal drug production.

Hovey, 33, with a doctorate degree from the University of Wisconsin, was arrested Sunday in Wilmington as he picked up a $260,000 installment on the alleged $1 million drug deal.

Yesterday, he was held without bail after a hearing before U.S. Magistrate N. Richard Powers in Wilmington.

An affidavit filed in the case in U.S. District Court in Wilmington charges that Hovey carried out a drug-trafficking scheme through confidential post office boxes, classified ads in the Wilmington News Journal, maps, and buried drugs and money.

He had allegedly asked that $900,000 of the $1 million be paid in gold because "gold is untraceable and will remain legal tender long after our government collapses . . . . Sometime in the near future (maybe in 1986) Uncle Sam is planning to replace our present currency with new stuff."

The substance -- 3-methyl-fentanyl -- is a "designer drug" that has a slightly different chemical composition from heroin. DEA put it on the list of illegal drugs last March 25.

Until now, it was virtually unknown on the East Coast, but DEA spokesman Robert Feldkamp said it has caused 60 deaths since Jan. 1, 1984, on the West Coast. Hovey allegedly provided one ounce of the substance, which is 1,000 times as powerful as heroin, to Bouldin. That is the largest seizure of the drug in the world, according to officials.

DEA estimates that one ounce -- worth $500,000 wholesale, and an estimated $28 million on the street in cut form -- is equivalent to 62 pounds of pure heroin.

Because of the potency, agents say that Hovey had provided detailed instructions that each ounce of the drug should be cut with 3,000 pounds of lactose, providing enough of the finished product for 13.4 million doses.

Clint Archer, a spokesman for Du Pont, said that Hovey had worked for the company for seven years doing research on organic chemical synthesis in the agricultural products department. He added that Hovey was fired Monday.

According to the affidavit, the investigation started Oct. 21 after a co-worker at Du Pont received a five-page anonymous letter and two vials of drugs in the interoffice mail. The co-worker, who has not been identified, turned the letter and drugs over to Du Pont security personnel, who called in the DEA.

The letter, which has been filed in court, offered the unidentified employee $10,000 in exchange for lining up a drug dealer to pay $100,000 in cash and $900,000 in gold for the drugs. The Du Pont employe was asked to take out a classified ad in the Oct. 31 Wilmington News Journal if he could line up the dealer. The ad was to say: "Happy 31st Birthday, Vermillion, Love, Joy, Kisses."

Communicating through a series of letters and advertisements, included in the court documents, Hovey allegedly talked about future deliveries of drugs:

"I can easily prepare new, unregulated, and completely legal designer drugs by just altering the structures . . . a bit. The only problem is that we have no way of knowing how potent they are until somebody uses them.

"I can keep an unlimited supply of the fentanyls available, despite the slow, lengthy preparation . . . . These dealings are going make us very rich . . . . Happy holidays to you and yours."