In their purple or red gowns and furred hoods, doctors were persons of important status." writes Barbara Tuchman of medieval European physicians in her "A Distant Mirror: the Calamitous 14th Century."

"Allowed extra luxury by the sumptuary laws," she goes on, "they wore belts of silver thread, embroidered gloves and, according to Petrarch's annoyed report, presumptuously donned golden spurs when they rode to their visits attended by a servant. The wives were permitted greater expenditures on clothes than other women, perhaps in recognition of the large fees the doctors could command."

And today?

An article in Medical Economics, a doctors' magazine, finds the 1979 Cadillac Eldorado "smaller but still a doctor's car" (though a survey shows "the front runner these days is Chevrolet," while Cadillacs and Lincolns still make the top 10").

Another article tells doctors "how to put your investments in the pink." An advertiser pushes estate diamonds costing from $2,300 to $140,000 as "rare investments."

Doctors are among brokers' best customers. "I get investment offers all the time," one doctor reported. "Lately, people have been getting doctors together to from syndicates to buy CAT scanners" -- $500,000, computerized X-ray machines -- "and lease them to other doctors or hospitals."

"Just now," says Medical World News, "hospital cafeterias are abuzz with talk of 'tax-advantaged' investments." But "don't get stampeded" into overpromoted tax-shelter and cash rollover schemes, this magazine warns.

Doctors often invest in medical buildings or other health enterprises. Involvements like these, and the simultaneous involvement of banks, insurance companies and other firms, "are beginning to freeze and lock in the system, so we are finding it harder and harder to make any changes," says Robert Derzon.

Derzon -- until September director of the federal Health Care Financing Administration and a former hospital administrator -- tells of one case; in the interest of cost-cutting, San Francisco officials tried to merge two hospitals. The merger was blocked largely by doctors with vested interests in their own practices and their investments in valuable land in the hospitals' vicinities.

American Medical News, an American Medical Association newspaper for doctors, recently exhorted AMA members to attend the "AMA Continuing Medical Education/Golf Program" at Doral Country Club, Miami. "Update your medical knowledge," the ad said, and "share a financial management seminar with your spouse."