AMERICAN HUMOR traditionally smells of liquor. There is no comic worthy of the Chateau de Ville who doesn't do a drunk routine, staggering, his speech slurring, his audience howling. But new markets are always opening up; in the last decade, dope has starred in a number of movies. Rarely has it played a bigger role than in Cheech and Chong's Next Movie, the touching story of three men, half a dozen women, and a duffle bag of marijuana.

Cheech and Chong have stuck with a successful shtick for years. People, they have discovered, find it a little thrilling to see illicit drugs on the big screen, thrilling enough that they will howl and yell and carry on at the sight of the drug. And so the pair, aging Chicano drifters, draw laughs with an elaborate series of sight gags and one-liners, all connected to dope.

The country cousin who ventures in to see his city relatives carries 50 pounds of grass--the Sack premier audience almost died a collective, happy death when he said he guessed it might be worth a few hundred bucks. Chong smokes billy-club sized joints and a cockroach he finds in the jar labelled "Roaches." Cheech sniffs salt thinking it's cocaine (and to climax this butguster drinks urine to slake his thirst). And at the end, a spaceship arrives to carry away all the pot bushes in a country field. Pretty humorous.

Together long enough to master timing and goofy faces, the pair are best when they forget about dope and concentrate on telling jokes. When hundreds of police arrive to arrest them, they innocently wander out the back way, mingle with the cops, and make an eight-track recording of their sirens. This may not sound funny, but it is--humor being relative. Later, they play the instruments in a music store so loudly that they catch on fire. They take over the stage in a nightclub and tell dirty jokes until a chair-throwing brawl breaks out. They wander through a massage parlor surprising patrons and playing their siren recordings. They even blow up their car by mistake.

The funniest moment in the movie is a 90-second pantomime--"out of the clear blue sky," as George Bush would say--when a man starts imitating an ape, cradling a beer can, contorting his face, twisting his arms. And the best line in the movie belongs to Cheech; after their high-powered car has left the police in the dust, he turns to his partner and says, "That was too easy--let's let them catch up and start again."

Ambition, in excess, can be dangerous. Cheech and Chong are fine as long as they stay in the barrio or the nightclub telling jokes and smoking dope. But the movie fails when it strives for epic humor. There are aliens, who appear suddenly, smoking dope by the treeful and sucking our heroes aboard. They give them "space coke," a powerful enough high to send the boys into orbit. And there are these awful dream sequences, including one depicting attempted necrophilia on the altar of some Mexican sun god.

The real message of Cheech and Chong's Next Movie, cleverly repeated again and again, is that dope is no more inherently funny than alcohol. There is no more substance to it, no mysterious properties that make those under its influence irresistibly hilarious. It seems likely that great comedians could do great dope routines--Charlie Chaplin Visits Jamaica--but it is not fantastically funny simply to light up a joint. If you have always enjoyed American screen humorists, however, go see this; it rivals anything Abbott and Costello ever did.