Today, as more than a century ago, the dream of furnishing oil for the lamps of China beguiles American businessmen. In 1873, Congress even went so far as to authorize a special heavier silver dollar - the ''trade dollar'' - for use only in the China and Far East trade. The Chinese, impressed by silver weight, wanted the heavier dollar, to replace a falloff in Mexican silver output. But within a couple of years, Mexican production was up again and United States merchants were stuck with their trade dollars. It was more than a decade before the coins could be redeemed.
One can welcome Premier Zhao Ziyang's mission to Washington and at the same time recognize a trade bonanza may again prove elusive.
China and the US have many divergent or conflicting goals. US-China friendship ''permits us to disagree'' was the way President Reagan aptly put it.
From the White House's perspective, the two forces behind the exchange of visits (Zhao to Washington this week and Reagan to China in April) are US business ambitions and what might be more generally called ''president handling.'' It is, after all, a presidential election year in the US. For some time the White House has had in mind a cycle of trips abroad and meetings with heads of state building toward an image of a President comfortable and active on the world stage.
For China, economic issues are more salient now than security issues, as Sino-Soviet relations have settled a bit. Sure enough, the Soviet ambassador to Washington was to be seen prominent among Premier Zhao's greeters in the US capital. The Soviets are busy courting the Chinese, too, promoting trade and other exchanges just like Washington.
The irony shouldn't be missed, either, that the Reagan administration, allegedly so pro-Taiwan, has allowed itself to get into this very visible exchange with the mainland leadership. There is no reason to think President Reagan has changed his limited view of the value of the mainland China connection, which has long been promoted by the wing of his party he has opposed. He's one of the last believers in a free and independent Taiwan and is not about to give that up.
Reagan is settling for principally a straight economic deal with the Chinese, renewing a five-year scientific and technological agreement, signing a new one on wider industrial and technological deals, and negotiating a nuclear-cooperation treaty.
For the Chinese, economic modernization is a high priority. They want access to Western technology. From their perspective, they can wait Taiwan out.
Basically, Zhao's visit seems to have put blessings on agreements already struck. For all the improved appearances, there seemed little evidence Mr. Reagan was himself negotiating substantively. By contrast, during Nixon's trip to Peking in 1972, the communique was written on the spot.
For the White House, the Zhao visit and Reagan's trip to China in April are no substitute for a Moscow-Washington exchange. This administration still wants a Soviet summit. That would be the real thing for 1984.
Even after the President's half of the China exchange in April, the administration's Asian policies will be largely undeveloped. If re-elected, he will have a lot to do in a second term. A China-South Korea-Japan policy is not enough. The Philippines under Marcos remain a problem. Reagan dropped Thailand and Indonesia when he omitted Manila from his itinerary last fall. Hong Kong and Kampuchea are unresolved. The Soviets still sit tight in Afghanistan. Islamic fundamentalism is strong in the region.
Again, we welcome Washington's steps toward better, friendlier ties with the world's most populous nation. The leap in the number of visitors from mainland China to the US that occurred after Carter's greeting of Deng Xiaoping in 1979 had begun to ebb last year, possibly after Reagan seemed to take lightly a promise to reduce gradually US arms sales to Taiwan.
All the attention to Zhao's Western suit and tie suggested the Chinese premier is himself no slouch at making impressions. China will be sending a large delegation of athletes and coaches to the Los Angeles Olympics this summer. The Los Angeles events offer the administration another opportunity to build on its improved US-Sino diplomatic relations.