FOR EVERY ALICE JAMES on an invalid's couch nursing some debilitating grievance, there was another 19th-century woman who impatiently burst the constraints imposed by middle-class convention and headed for the hills. Until now Margaret Fountaine's name has been unknown, but a sealed diary, opened 28 years after her death, reveals an ardently liberated spirit -- or perhaps semi-liberated; for though in her pursuit of diurnal lepidoptera she bicycled alone through the wilds of Hungary and clambered about Sicily unchaperoned, she was besotted by men and up to the threshold of old age drew them to her like the rum and honey she smeared on treetrunks to attract butterflies.

Born to a well-connected Norwich family in 1862, Margaret suffered at an early age from what the local doctor diagnosed as a monomania: the love of men. Her diary records a tumultuous procession of passions for curates, cornet players and choristers -- to her eyes "remarkably good looking," though all too often "of quite low origin." What she described as the noblest love jof her life was for an Irish ne'er-do-well named Septimus whom for seven years she besieged with longing glances, unanswered letters, and finally, when she came into her inheritance, with money. At 28 she received from him her thrilling first kiss; next came their engagement. Plummeting into social abysses she had never dreamed of, she happily drank tea with his relations over a shop, but Septimus soon skipped and Margaret was left to nurse a virulent grief and humiliation. She found a cure that was to give her much pleasure throughout life and some torment to many men: "Perhaps it would stay the raging fires of passion that rent my breast if I learnt to kindle like fires in the breasts of others?"

She tried a trip abroad and knew at once she had discovered her vocation: to travel hopefully, with a beast in view. Armed with net and killing bottle she chased butterflies over Swiss meadows, and evenings, surrounded by young men, "began to learn that it was a delightful pasttime to trifle with those emotions hitherto held by me most sacred." "I was born a naturalist," she declared; she was a born allumeuse too, as the French put it, who all her life was to relish what the delightfully amused and indulgent editor of her diaries calls "a little ladylike scalp-hunting."

Henceforth she did only a brief annual tour of duty in dreary England, placating a dragon mother and attending charity bazaars "to counteract the delights of roving over foreign lands with a tolerably well-lined purse" in pursuit of Greater Tortoiseshells, Roselanas, Catagrammas, and good-looking foreign men. For a while, however, she studied singing in Milan with a handsome teacher and announced, "If Fate wills I am to give up my ranbling life over the mountains . . . to stand before the footlights, well so it must be." Freedom easily won out over the theater -- a place of "vile dissipation," in any case -- and she returned to hiking "from one place or even one country to another with as little concern as if I were passing from one room into the next," sending her luggage on ahead.

In Corsica, accompanied by a wild-looking man who offered to carry her basket, she refused an invitation to watch butterflies mating, and thanked providence for its "special protection over a pure and high-minded woman, which no man however base can break through." But virtuous men didn't get very far with her either. A gentle Italian doctor, regrettably "without chic or swagger," gave her a welcome chance to punish his sex. She encouraged him, then departed for England, planning not to answer his letters: "Now at last I shall be able to have my revenge.I know what it is to wait for letters that do not come." She was not a little chagrined when he turned the tables by suggesting she consider him "as an old friend, or if you prefer, a brother." "The love of a true, good man is forever denied me," she concluded early on. "I will just get all the pleasure I can from the bad men I meet, that is to say going to the edge of the precipice, but without falling over it!"

In Palermo, aided by a becoming new hairdo, she put her resolution to the test, picking up boys on the street and, at her hotel, a bearded baron. He was charming, but when he frankly pressed her to complete their relationship, she balked. "I was quite infatuated by this man, and I might never have such a lover as he was again, but I was obdurate." The frustrated baron nevertheless converted her to his views: "He taught me to feel . . . that free love was the best, and often the purest -- only not with him!"

The lower orders were easier to handle. The pleasure she had flirting with a youth who hunted butterflies with her in the Sicilian hills seemed unthreatened by sexual demands, though he was soon pointing out the activities of birds and butterflies around them. She lay in his arms under a fig tree, but resisted further advances. "What was I to do? I could not so lower myself as to allow the son of an hotel proprietor to kiss me!" From an aged professor she did accept kisses, but next morning cruelly informed him that she had scrubbed her face hard where his lips had "polluted" it. "Con sapone?" he asked. "Yes, with soap, and plenty of it!"

It is hardly surprising that such a woman could handle the advances of a Hungarian doctor who came into her bedroom for a morning kiss; indeed, she could handle far graver threats. Out after a rare species in the Hungarian mountains she barely escaped a murderous-looking character on a desolate stretch of road by her aplomb and speedy biking, refreshing herself after this escape with eight large beers. Unfazed by the language, she joined a Budapest butterfly society's outings, and in the company of a handsome member longed "to feel strong arms around me and a man's heart beating against my own."

But it wasn't all fun and games. How little her mother's friends who admired her butterfly cases knew what hard work they meant -- maybe 10 hours on foot with only a meal of bread and sheep's milk straight from the udder -- or guessed at her amatory adventures. The excluded Englishmen: "I suppose that Englishmen do make love sometimes, too, though I can't imagine what it would be like."

Just short of her 40th birthday she set off for Syria accompanied by a blond dragoman. This was Khalil Neimy, a young Syrian who was to be the love of her life -- excepting, that is, the swinish Septimus. Neimy was smitten by Miss Fountaine, kissing her hand fervently before breakfast. Never had she met "quite such a weak, contemptible character," but soon enough, in her "loose" moods, she grew accustomed to his kisses on her hands and arms. When he attempted to include her face she was enraged -- "I trembled from head to foot in my fury" -- but next day "sank lower than I had ever sunk before; the very audacity of the man overcame my sense of what was right and proper. Why are men such animals?" Soon, however, they were engaged. She was divided between pleasure, amusement and shame -- when they married they would certainly have to live in Milwaukee, where her social degradation would be inconspicuous. However, she was not to be a bride, for she discovered Neimy had earlier contracted an arranged marriage. She readily forgave him. Henceforth they regarded themselves as man and wife in God's eyes, but whether this meant going over the brink she does not say.

And yet, when a perfect stranger, a British vice-consul posted in Turkey, wrote to ask her hand in marriage she was of two minds. After she had dubiously accepted him (Neimy's reactions are unrecorded), his vulgarly possessive letters, addressing her as "Maggie," soon showed her her folly, which became clearer yet when he threatened to sue for breach of promise. "Such a step," she wrote him witheringly, "is rarely, if ever, resorted to by one of your sex, nor indeed would any woman in our class of life stoop to anything so degraded."

She and Khalil (now "Charles") gamely traveled on all the continents, augmenting the great butterfly collection, but in 1914 the war put a temporary end to Miss Fountaine's footloose life. Here the editor chooses to end his beguiling pursuit of her adventures, though a tantalizing epilogue offers glimpses of her clearing tree stumps in Australia; earning 25 cents an hour collecting spider nests in California; exploring the great South American rivers (still pursued by amorous men); surviving an African train crash by leaping off into the bush; galloping 45 miles a day, aged 70, in chase of butterflies; playing pool in a Virginia saloon; lunching in Paris with a lepidopterous Rothschild. Will not the editor relent and give us these further adventures?

Miss Fontaine once wrote that she had come into the world unattended by a doctor and expected to go out the same way. She did. In 1940, while out with her net in Trinidad, she suffered a heart attack and died in a nearby monastery. Her 22,000 butterflies ("a beautiful but -- to the layman -- slightly chilling sight, so much dead brilliance," Mr. Cater remarks) she left to a museum as the Fountaine-Neimy collection, and along with it her astounding diary. This pretty book (deceptively reminiscent of the Edwardian Lady's dreary nature notes) is adorned with photographs of the dead brilliance, meticulous watercolors, and prim photographs of the diarist. A young entomologist who met her when she was past 50 described her as a "tall attractive, rather frail-looking, diffident but determined middle-aged woman . . . the strongest impression she gave me was of great sadness." Through the sadness he quickly spotted what makes her diary such fun to read, "self-deprecating flashes of humor that quite transformed her."