The six-day auction of the Robert von Hirsch art collection ended last night with a record $34.1 million in sales.

The total is more than three times that reached at any previous art auction. When the last item, a Picasso ink sketch of a mother and child, was sold at Sotheby Parke Bernet's Mayfair sales room last night, the crowd of dealers broke out into discreet applause.

The final night's sale of Impressionist and Post-Impressionist drawings lacked the electric tension of earlier sessions where some objects fetched $1 million and more.

Even so, the hardened dealers who dominiate the audiences at such gatherings broke out into murmurs of conversation at the high prices bid. A watercolor by Paul Cezanne, "Still Life With Green Melon," was purchased by an anonymous New Yorker for $550,000.

His bid, over the transatlantic telephone, was the largest sum ever paid for a drawing by a modern painter, For his money, he got a typically Cezanne treatment, transforming fruit and a glass into spheres, cylinders and cubes.

Until now, the most ever paid for a modern drawing was $460,000 for another Cezanne watercolor.

Sotheby's also claimed new highs for drawings by Vincent van Gogh, Paul Gauguin, Georges Seurat and Berthe Morisot.

A Van Gogh sketch in brown ink and pencil of tiled rooftops at Saintes-Maries sold for $380,000. Again, the buyer was an unnamed bidder in New York. For this one night, the German dealers who have dominated the sale here took a back seat. This was because few works by German artists were auctioned off.

Perhaps the most remarkable price was the $260,000 bid - again in New York - for a small Cezanne watercolor of one of his famous studies of bathers. Only 5 inches by 8 1/2, it is a page torn from his sketchbook, a model for a work in progress.

Until last night's final sale, the heavily promoted auction had brought in $29.6 million for the anonymous heirs of the Von Hirsch estate - minus the commission that Sotheby's negotiated with them. The previous high for any auction was the $11 million Sotheby's sold from the Mentmore-Rothschild Collection here last year.

The high prices frequently recorded at the sale can be traced to two forces, inflation and German nationalism. Leading German museums, with cash from the federal and provincial governments, banded together to bring home medieval enamels, watercolors, porcelain and furniture attributed to German artists.

Dealers frequently work together at an auction to drive off competitors and save themselves from bidding against each other. But the German consortium involving at least 10 dealers from London, Zurich and elsewhere, may have set a new high in this regard spending more than $20 million.

Appropriately enough, it was organized by Hermann Abs, former head of the Deutsche Bank, a veteran cartelist and once the most powerful man in the private German economy.

Among other things, the Germans picked up a rate if modest watercolor by Albrecht Durer for about $1.2 million, a 12th-century enamel medallion of an angel for $2.2 million and another 12th-century enamel arm band for $2 million.

The spectacle would likely have pleased Von Hirsch, a rich businessman with no affection for the nation that had forced him into Swiss exile. He once toyed with the idea of giving his collection to the Basel museum, but revenge and his heirs' interests prevailed.

"If anyone wants my art treasures, they can pay for them," Von Hirsch has been quoted as saying. "And that goes for the Germans who drove me out of Germany."

That sentiment was reported this week by Rudolph Walther, the German deputy who helped clear the way for the $9 million federal subsidy to the successful German museums.

It stands in contrast to the statements by Sotheby's that Von Hirsch ordered an auction so collectors could enjoy the "thrill" of competing for his works.

Dealers who lost out to the German cartel were not bitter. Everybody in the art business benefits when prices rise because agents collect a percentage of each sale.

So Hugh Leggatt, a London art dealer, declared: "The Germans have acted as a family. They have set an example which this country ought to follow. We are in desperate danger of losing our heritage."

Another London dealer said, "There is no resentment towards the Germans, none at all. They have been rather impressive and haven't hurt anything. We like to see prices main-have been fetching.

The only drawback, he suggested, was that the Germans might have made things a bit difficult for a dealer who is offered an object similar to those sold for a high price at Sotheby's and then finds he can't match it.

The trade tends to believe that the Von Hirsch sale will have only a limited effect on the general level of art price. Souren melikian, the veteran sales room correspondent for the International Herald Tribune, noted that a renaissance statue and dish, each selling for over $60,000, went at triple or more what similar objects

But this, he said, reflected the Germans' belief that a "National Heritage? was at stake. Melikian predicted that "the usual price structure" will prevail in less charged circumstances.

Indeed, one dealer insisted that the prices paid for works without a German connection "weren't out of all proportion." However, on Monday night, a portrait of Paul Cezanne by his friend Camille Pissarro went for $550,000 to a collector bidding over the transatlantic telephone from New York; and a Matisse "Still Life With Sleeper" that lacked Matisse's vibrant color fetched $570,000.

At least one U.S. museum, in Toledo, Ohio, sent over a man to look at drawings. He decided that the hoopia would drive prices too high and went home. But the Cleveland Museum of Art made at least two expensive purchases, a Rembrandt sketch of a mogul monarch for $300,000 and a 12 century Italian ivory plaque for $350,000.

In addition, every buyer will pay Sotheby's another 10 percent, giving the house about $3 million in addition to the Von Hirsch family fee.

Whether anybody but the Germans could have mounted a cartel like the one seen here is a question among larger nations. Only the Japanese enjoy the same surpluses in their balance of payments.

Arab oil states, of course, could do the same thing but are not regarded as likely candidates. "At this point, Arabs are chiefly interested in expensive furniture, jewelry and large, pictorial canvases," a dealer who knows them said.

Yesterday the Saudi Arabian riyal was not even on the big, electric scoreboard with which Sotheby's instantly converts bids in pounds into other major currencies. CAPTION: Picture 1, Treasures of the Von Hirsch collection: dressing table, which sold for $371,000; Picture 2, the Mosan Medallion, $2.22 million; Picture 3, an Albrecht Durer watercolor, $1.2 million. Washington Post Foreign Service