Black Blarney and the Spinster : BLACK BABY <i> by Clare Boylan (Doubleday: $17.95; 210 pp.) </i>

Let charm keep away from mirrors. Also, from reflecting shop windows, sidewalk puddles with the sun on them, and the sympathetic flash of a reader’s eyeglasses.

Clare Boylan’s charm is authentic, and her workshop is her own, even if sometimes it resembles an elf’s. Her characters act and speak with a piquant originality. But they somehow caught sight of themselves before coming out to meet us, and they liked what they saw.

In “Black Baby,” Boylan’s fourth novel, what is moving goes hand in hand with what is touching and a little touched-up; so does wit with whimsy, and a streak of wildness with a swatch of decoration. It is, or seems to be, the story of the bizarre meeting and friendship of a lonely Dublin spinster and an energetic, young black woman, warmhearted but tough-minded.

Part of it really happens, and part is imagined by Alice, the old woman, as she lies in a dying coma. Reality is never very firmly established in the book--it is one of its attractions--and things often might be, and sometimes are, quite other than they seem.

Take Dinah’s arrival. Alice, who lives alone, mourns her father, is unable to keep his garden from going wild but sedulously winds his 13 clocks, has been weeping. Her nephew and his family have just been to visit with a present. It is an old gramophone, but to Alice it has a funereal look.

Dinah rings the bell, and Alice, who can’t see very well, is certain it is a burglar and attempts a feeble grapple. The burglar, however, kisses her--”For a while Alice had the sensation, not unpleasant, that she was dancing with a bear”--quotes Scripture, and asks for money for a religious society. In fact, as we learn only at the end, Dinah had come to burgle, carrying a large wrench in her bag, but she can’t bring herself to it.

Instead, she rebukes Alice for moping. “You cry a lot,” she says. “I heard you crying before I came in.” Alice replies apologetically: “It’s my birthday. They gave me a coffin.”

Alice sends Dinah away but something begins to sprout in her loneliness. Through a misunderstanding that the younger woman does not clarify, Alice gets the idea that her visitor was the baby whom, as a schoolgirl, she gave money to “adopt,” and that she has come all the way from Africa to see her. Dinah, in fact, is a Londoner.

In a series of further misunderstandings, Dinah is summoned back, feels snubbed, leaves, comes back again, again feels snubbed, and leaves once more. Alice longs for her imagined “daughter,” but she is too stiff to open her arms wide enough for someone as touchy and impulsive as Dinah.

Eventually, or so it seems, Dinah does move in. She fills the house with warmth and light. She clears the tangled garden. She brings friends to strip and redecorate. She brings a man she has picked up, who shocks Alice by putting on her father’s dressing gown, but reconciles her by being tender and polite and leaving five pounds to have it dry-cleaned.

Alice learns how to enjoy things. There are parties, a bonfire and sausage roasts in the garden. And Dinah, who works in a cafe, turns it into a great Dublin success with her bits of Scripture and her talent for a kind of advice-to-the-lonely table-hopping. Or so it all seems.

Some of this, as I have said, never happens. If Alice is brought to a late flowering, it is partly through her own imagination.

Of the two, Dinah is the better drawn--in part, because we are left with an element of mystery. Some of her tough love for Alice is an illusion; in fact, Dinah, a loner, is out for herself. Yet there is something warm and open about her, along with a stoic acceptance of dangers and pleasures, and a wonderfully orotund way of speaking.

She is firm and didactic with Alice. “You can get books to improve your memory,” she tells her on the phone, when Alice says she is going to get a pencil to write down her number. When Alice worries about the expense of turning on the heat, Dinah retorts: “You may be half dead, but my blood is not yet ambient to the morgue.”

She strikes up a pub romance with Figgis, a stout Dubliner who teaches her to sing “Kevin Barry” and gets off an undoubtedly offensive, probably used, but in any case quite lovely remark, to the effect that not changing your socks “is the Irish form of contraception.” (Boylan is Irish.)

Sometimes, as we admire Dinah, we get the feeling that she is admiring herself too. With Alice, and her pre-Dinah menage, the sense of a strained and self-indulgent decorativeness is more noticeable. When her clocks strike, they strike: “spinster, spinster, spinster.”

The theme of an old and frozen character being thawed and rejuvenated by a stranger is not original, but Boylan’s blurring of the line between what happens and what is imagined gives it some freshness. Amid the adornment, there is writing that genuinely shines. But there is a lethargy to the book that seems proportional to the quickness and reflexiveness of its author’s fancy.