BUT FOR some adventurous types who came here from Europe in the 18th century lusting to explore the frontiers of civilization, few examples of the remarkable artifacts of the central North American Indians would be preserved."

The Speaker should know. He is Ted J. Brasser, the ethnologist at Ottawa's National Museum of Man. He assembled the splendid 191 highlights of the museum's collection that opened last week for a six-month run at the Renwick Gallery. "It is the cream of the collection for tribes east of the Rockies," he says. "About 90 percent of the objects were acquired from European collections," says Brasser, himself a Hollander.

"The phenomenon of collecting exotic curiosities is an old and distinct part of European cultural and intellectual history," writes Brasser in the authoritative catalogue.

"Nearly everyone connected with early European exploration and settlement of the New World collected native arts and crafts and sent them back to the Old Country, North America then being a frontier without museums. Even the king of France, sometime after 1740, had a collection of Indian curios assembled for the entertainment of his son. Some of the objects were brought back by returning German mercenaries, the Hessians employed by the British against the American revolutionaries.

"Our conception of native arts and crafts would have been extremely hazy without the wide-ranging interests of European collectors," writes Brasser. It is doubtful that "they would have survived all there years in Indian hands. Take, for example, the large-scale destruction of medicine bags by the Ojibwa and other followers of the propher Tenskwatawa in 1809, or the widespread custom of burying the deceased with their most cherished possessions."

One of the swashbuckling Europeans who took these artifacts back for their private collections was Sir William Johnson. "He was the first Indian agent appointed by the king, sometime in the 1750s," said Brasser. "He was stationed in Albany and married a Mohawk." A highlight of the collection is a sword belt Sir William had made for him by Indian craftsmen out of woven porcupine quillwork on warp and waft of Indian hemp-still in what appears to be perfect condition.

Another such adventurer was Sir John Caldwell, fifth baronet of Castle Caldwell, County Fermanagh, Ireland. A painting of him in spectacular finery madeby the Indians is on the catalogue cover. The huge feather and plume headdress makes him look like he's wearing am elaborate centerpiece for alarge dinner party. His extended arm holds a long tomahawk. Stationedat Fort Niagara and Fort Detroit, Caldwell was made chief of the OjibwaIndians (known as the Chippewas in the United States). Unfortunately the painting is not in the show.

In fact all the pictures that accompanythe objects are reproductions. The Renwick has borrowed four George Catlins from the National Collection of Fine Arts to balance this out.

The exhibition has works by four groups of tribes-the Northern Plains Indians, the Great Lakes Indians, the Northeastern Forest Indians and the Huron and Iroquois. About 30 percent of the objects were made in what is now the United States and the rest in Canada.

The show is called "Bo'jou, neejee! Profiles of Canadian Art" after a common greeting between theIndians and the Europeans, combining an abbreviated "Good day" in French with the word for "friend" in Ojibwa.

In the exhibit are headdressed,stone pipe bowls, snowshoes, wampum belts, silver breastplates, war clubs, coats, knives, sheaths and many other items.

The core of the Canadian museum's holdings on this sujecct is the collection assembled by the late Arthur Speyer, an entomologist and mineralogist of Hamburg, Germany. The museum bought it four years ago for "about$4 MILLON."

By today's standards it was a bargain, because in the interim American Indian artifacts have become hot auction items at Sotheby Parke Bernet and Christie's. From the Speyer collection, Brasser particul arly prizes a full-lingth moosehide coat tailored in the European style, with an open front, but with aboriginal designs in brilliant colors (before the arrival of the white man, Indian men wore caftans). "One might bring as much as $6,000 on the auction block today," he estimates.

A nptable difference between these artifacts and those of the Southern Plains Indians is the common perference for dyed porcupine twills over beads in making the designs.

"The women would take the twills, which are hollow," says Brasser, "and flatten them with their teeth. And then dye them."

Perhaps the most luxurious item is a sealskin coat with appliquedfloral designs in moose hair, some of them edged with red silk. There are insets of comtrasting white fur, representing the head of a pipe-smoking Indian, a tomahawk and a beaver. And all of this is lined with redsilk brocade. In its sumptuousness, it could as well be Russian as Huron Indian. The coat was made about 1845.

Since buying the Speyer collection, the Canadian museum has acquired three more European collections,competing with institutions like New York's museum of the American Indian and the Smithsonian.

There is one rather curious twist. Several of the exhibit's most beautiful objects are made not by the Indian, but by the white man for the Indian. They are silver pieces, including a superbly crafted headband, created for the Algonquins.

Notes Brasser, "They did most of their business in Philadelphia or Montreal in those days."