At the Bronx Latin School, one of New York’s multiplying number of small themed public middle and high schools, Latin is what Alfred Hitchcock used to call the MacGuffin: a plot device that grabs our attention while the story has a larger purpose.

The school’s larger purpose is simple: to get students, most of them “struggling with literacy,” as the founding principal, Leticia Pineiro, said, to read and also do math at grade level or better.

The three-year-old school is gambling that teaching Latin will initiate poor and working-class students into the mysteries of how any language — especially English — works by illuminating the long-neglected art of grammar and enriching their English vocabulary with Latin roots.

In Peter Dodington’s seventh-grade class the other day, the talk was about Latin verbs. With “portat” — he, she or it carries — Mr. Dodington, 61, elicited from his students English derivatives like portable and teleport. That led to a discussion of the Greek root, tele, for far off, which yielded a new understanding of how words like telephone (sound that travels far) and telegraph (writing that travels far) are shaped.

The class then switched to translating the fable about a shepherd saved from having to fight a lion because he had pulled a thorn from its paw. The story was right out of the textbook “Cambridge Latin Course,” used by elite private schools, and the students seemed to enjoy translating phrases like “cur lacrimas, leo?” and “cur me non consumis?” “Why are you crying lion? Why don’t you eat me?” In the era of Harry Potter and recondite medieval mysteries, the students seemed enchanted by Latin’s esoteric, exclusive aura.

“Nobody knows what you’re talking about,” said a proudly grinning Christian Graham, 14.

A visit to Bronx Latin suggests that its approach may be working. Moreover, on this year’s state English test, 50.9 percent of seventh graders read at grade level or better while only 31.8 percent of seventh graders in the surrounding South Bronx region performed that well.

But the visit also did not allay some of the doubts experts raise about small schools, almost 200 of which have been created by the Bloomberg administration in the last three years, often with foundation money. For example, there remains the distinct possibility that higher reading scores at Bronx Latin might be the result of self-selection: families or guidance counselors urging Bronx Latin on children may have higher ambitions for them.

Though she never studied Latin, Ms. Pineiro, 40, a graduate of the private Dalton School in Manhattan and Wesleyan University, deeply believes in her school’s focus. She is an intensely dedicated leader on whom little is lost, the kind who will stoop to pick up a student’s dropped tissue and correct a novice teacher who lets students watch a film without requiring note-taking. She is delighted to be returning to the Bronx community where she grew up.

“This is my passion, this is my baby,” she said of the school.

But people who have studied such schools wonder if idiosyncratic — carpers might say gimmicky — missions like teaching Latin can sustain themselves once their founders move on.

“What happens when that initial spark is gone, when you have second-generation leadership?” asked David C. Bloomfield, the head of the Citywide Council on High Schools, an advisory parent group. Mr. Bloomfield said he supported the concept of small schools, but he has filed a discrimination complaint with the federal Education Department saying that the city has denied spots in small schools to special education students and those who are not proficient in English.

Ms. Pineiro, though, believes that the school can thrive without her. The key to Bronx Latin’s success, she said, is the after-school hours that teachers spend learning its methods, like structured collaboration among colleagues who share students, and the insistence on informing parents when children stumble. She promises that, when the time comes, she will train a successor in the school’s methods. But will another leader be as demanding?

And there are other questions. In a school the size of Bronx Latin, which offers grades from 6th to 8th and will add one grade a year through 12th, students may not have access to advanced classes preferred for college entrance or to extracurricular activities. What happens when students move — as so many children from poor or troubled families do — and attend schools that do not offer Latin? What happens when teachers like Andrew Goldin, who joined Teach for America on two-year contract, move on to other careers? Latin teachers willing to chance public schools are a precious commodity.

WITH just 156 students in the school, classes are almost like seminars; Mr. Dodington’s class had 15 students. But there is already jostling over space with three programs that share the building. Studies have shown that mainstream schools are being squeezed for space because of the small schools placed in their buildings.

Mr. Bloomfield, who also directs training for principals at Brooklyn College, and other critics, like the education historian Diane Ravitch, said too many small schools have been formed with inexperienced, even if enthusiastic, staffs. Although attendance is higher and violence down, there is little reliable information on whether they are actually improving learning.

Bronx Latin is something of a daring adventure. Latin is usually the province of private academies like Horace Mann, where students from middle-class homes are already champion readers,

“When I think about Latin,” said Mr. Goldin, 23, “I certainly think of an environment where kids are reading at grade level and have a grade-level vocabulary, have study habits, get their homework done. That’s not the experience the majority of our students have had by sixth grade.”

Mr. Goldin and Mr. Dodington, however, are eager to prove the conventional wisdom wrong.

“I always thought it would be an interesting goal to teach Latin to everybody,” said Mr. Dodington, whose classics career includes a stop at the elite Collegiate School. “Take a subway car of people — that’s what we do.”

Latin works well with children who are not strong academically, he said. “It’s very organized, very transparent,” he said. “There’s a rule for everything.”

Mr. Goldin, a graduate of the University of Pennsylvania who in contrast to the button-down Mr. Dodington dresses casually and has shoulder-length hair, is brilliant at running Socratic discussions, where he asks leading questions to guide students to their own well-grounded conclusions. He had a class analyze the meaning of justice through an Indian fable about two kings, one who meets the good with goodness and the wicked with wickedness, another who conquers evil by his goodness. Practically every student had something to say.

“If you give him attitude, he’s going to give you more attitude than you give him,” is how one boy described one king’s philosophy.

Mr. Goldin repeatedly reminded the students that they could not just state random thoughts. “Is that your opinion or is that based on the text?” he asked. He also trained the students to listen, gently pulling a pen away from a boy fiddling with it distractedly.

Whatever the questions about Bronx Latin, membership in a rarefied group that can decode a dead language is a source of pride that is a powerful motivator.

“The idea we’re offering Latin helps by itself,” Mr. Dodington said. “It’s kind of a vote of confidence in the kids.”