Fingertip Drug Analysis

The detectives have raided a house and found some suspicious white powder or liquid. One of them puts his or her finger in it, then either sniffs it or tastes it. They pronounce it's heroin or cocaine or whatever. Or if it's phony drugs, they announce "Powdered sugar!"

Also done by drug-dealing baddies.

Seen in almost every 1970s Cop Show.

The mysterious white powder (almost) never, ever, ever turns out to be a deadly poison that kills our hero outright, despite the fact that he's found something, doesn't know what it is, and is stupid enough to put it in his mouth.

Despite the obvious hazards (not to mention the fact that a police officer could get in serious trouble if they were tested and found to have a drug in their system), this was Truth in Television to the extent that certain drugs (opium, for example) have a distinctive taste or odor. Cocaine can be identified not by taste, but by the way it instantly numbs where it touches. However, any modern police officer is loaded with all kinds of test equipment for just this - without it, it's just a cop's word on the stand. But if a chemical reaction proves it's really drugs, it's a lot harder for a lawyer to disprove, and a lot safer for the cop (see the Real Life entries) as well.

If the substance is blood, you're performing The Ketchup Test. For any case of testing mysterious substances by taste or smell see Sniff Sniff Nom.

Anime & Manga

 * In the anime version of Dominion Tank Police there's a scene where Brenten tastes some mysterious liquid, then is informed a moment too late that it's a urine sample. (The manga had no such gag, but it's exactly the kind of thing Brenten would have done.)
 * In Great Teacher Onizuka, Onizuka needs more than a million yen to pay for a vacation trip and his buddy cop Saejima gives him bags of white powder, supposedly cocaine, that are apparently worth millions. Kikuchi immediately pokes his finger in the bags and tastes the powder, and says that it is just ordinary flour. Onizuka is angry at being cheated, but Saejima replies that "I never said it was cocaine! It is good flour! You could sell it to a bakery!"
 * In a chapter of Gokusen, one of the teachers at the school discovers a mysterious pill. The protagonist, a Yakuza Princess grinds it between her fingers and tastes it, to the shock of her colleagues. Seeing their reaction, she claims that it's just an antacid, but identifies it to herself as drugs. Seeing how her Family are Neighbourhood Friendly Gangsters who supposedly don't deal drugs, it's kind of odd that she would be able to tell what the substance is/why she would think of doing this.
 * In Rurouni Kenshin, Megumi drops a small packet on the ground when hurrying off to treat Yahiko, who was just poisoned by a ninja. Sanosuke picks up the packet and takes a small taste of the white powder inside. He discovers that it was opium, and angrily questions why she would have this in her possession.
 * Played completely straight in episode 2 of Space Adventure Cobra: The Psychogun where Cobra tastes a vat of some glowing substance the villain has hidden away, and concludes that he is smuggling drugs.

Comics

 * Judge Dredd once identified a shipment of illegal sugar by tasting.

Film
"Tango: "Mm...wanna get high?""
 * The James Bond film For Your Eyes Only -- Bond identifies raw opium by taste. He does the same in The Living Daylights. The same substance looks slightly different in both films.
 * Spoofed in The Princess Bride. The Man in Black kills Vizzini with the "odorless, tasteless" deadly poison iocaine. Later, Prince Humperdinck finds the vial which originally held it, sniffs it... and immediately identifies it as iocaine.
 * Though it should be noted that in the book he identified it as iocaine because of the lack of any odor and the fact that a man obviously was killed by a fast-acting poison beside it. Notably he says "Iocaine, I bet my life on it." meaning he couldn't decidedly identify it, but given the circumstances and evidence, made an educated guess.
 * Subverted in the movie Showtime, which shows an undercover detective verifying a drug buy with a small chemical apparatus, and later, when William Shatner as Himself demonstrates the Fingertip Method, he is met with the question "And what if it was cyanide?"
 * Frank Oz identifies the drugs planted on Dan Aykroyd in Trading Places as PCP using this method. Which is insane considering what even a tiny amount of PCP can do.
 * Also spoofed in the Utah film The Singles Ward, when a young woman is arrested for breaking in to what turns out to be her own apartment. A plastic tub full of white powder is handed to the senior partner (played by a Morning Radio Personality), who takes a deep whiff, buries his finger in it, sticks the whole finger in his mouth, and pronounces it "Tide".
 * In the third Terminator movie, the T-X analyzes blood samples this way. A bit of a variation in that she knows it's blood (der), but has to find out whose DNA it is.
 * Justified in the T-X is a machine and as such it is entirely reasonable that it would be built to be able to perform that test with built-in equipment.
 * Moreover, unlike a human cop she's highly unlikely to be poisoned as a result of tasting something nasty.
 * Spoofed in Charade, when Audrey Hepburn and Cary Grant are going through her late husband's luggage to see if they can find something valuable enough for him to have been murdered for. They find a tin of what appears to be tooth powder; at her urging, he does the test... and concludes that either it's peppermint-flavoured heroin or it really is tooth powder.
 * The buddy-cop movie Tango and Cash opens with Ray Tango arresting two punks, who have driven an oil truck well outside his jurisdiction. The highway patrol arrives on the scene and chides him for his recklessness, and a search of the truck reveals nothing but oil. They ask if he thinks he's Rambo, to which Tango calmly replies, "Rambo...is a pussy" before shooting the oil tanker, revealing a steady stream of white powder. Tango cups his hands under the stream for a few seconds, then licks the resulting pile of powder in his hands.

"Connor: (tastes the mysterious white powder) That's heroin.
 * In the movie version of Harry Potter and The Half Blood Prince, Dumbledore does this to some blood that's dripped onto Harry's forehead from the ceiling, but doesn't immediately comment. After he locates Slughorn, he identifies it as dragon's blood (which, as the alchemist who discovered the twenty uses of the substance, makes sense) and reveals that it's what made him positive the ransacked house was faked.
 * Spoofed in The Boondock Saints 2: All Saints Day:

Murphy: (Beat) How the fuck would you know that?

Connor: Fuck you! I know shit!"


 * Basil does this in The Great Mouse Detective, when he suspects someone of spiking his drink.
 * In Dumb and Dumber a state trooper suspects that the two protagonists are drinking alcohol while driving so he orders them to hand over the open bottle they have and takes a drink to confirm this. He really should have tried to smell it first since.

Literature
"Detritus blinked at his finger, which was still white with the dust, and sidled over to Carrot. "Did I just lick dis?" he said.
 * Spoofed in Terry Pratchett's Feet of Clay, where Constable Flint (a troll serving in the Ankh-Morpork City Watch) tastes a mysterious white powder he suspects to be Slab, a troll hallucinogen, and says, "Yes, this is definitely Slab wurble wurble sclup," and has to spend three days tied to his bed until the spiders go away. The same thing happens to Sgt. Detritus later in the book:

"Er, yes," said Carrot.

"T'ank goodness for dat," said Detritus, blinking furiously. "'D hate to believe dis room was really full of giant hairy spide... weeble weeble sclup ...""

""How many times do I have to tell you," I howled, "I haven't been to the village shop!"
 * Ironic especially since Deterius was the one who relayed the fate of Sergeant Flint and stated how dumb it was
 * Earlier, Vimes found a mysterious bag of white powder in his desk but explicitly refused to taste it, instead asking the on-staff alchemist to see if it was arsenic. Shortly afterwards Carrot did use this method. On a mysterious bag of white powder he'd just seen Vimes stuff a handful from into his mouth. It turned out to be sugar, Vimes having swapped out the bag for one from the canteen.
 * And Then There Were None - The doctor puts a very-very-small amount of a mysterious substance on his finger and tastes it very cautiously. He is instantly able to tell it's cyanide.
 * In Agents of Light and Darkness, John Taylor performs the fingertip touch-and-taste test on a statue, and confirms it's a human who's been transformed into salt. Only in the Nightside...
 * Mentioned in Stephen Fry's autobiography Moab Is My Washpot, when he recounts the head boy at his prep school catching him with stolen sweets.

"Yeah, yeah, yeah. Sure you haven't. And what have we got here then?"

If the memory weren't so absurdly anachronistic, I could almost swear that Pollock ripped open one of the flying saucers and put his tongue to the sherbet like a Hollywood cop tasting white powder."


 * In Rudyard Kipling's The Second Jungle Book story "The King's Ankus" Mowgli discovers some men who have died after eating poisoned bread. One taste (of the bread, not the men) is enough for him to identify the type of poison. Kipling justifies this as necessary for survival in a jungle full of poisonous plants.
 * The Curious Misadventures Of Feltus Ovalton has Percy about to do this to a packet of concentrated itching powder; fortunately, Feltus stops him.
 * Maureen does this (cautiously) in Robert Heinlein's To Sail Beyond the Sunset while searching out-of-control teen daughter Priscilla's room, when she finds a bag of white powder. She concludes it's cocaine from the numbing effect (she did also find what she decided was marijuana). She briefly considers turning the stash over to the police in hopes they'll find her daughter's dealer, but decides it would be pretty close to impossible to convince the police the stash is her daughter's rather than her own, and flushes it.

Live Action TV
"Cop: And what's this?
 * Bodie, Doyle and Cowley regularly do this in seventies action show The Professionals.
 * Also spoofed in one episode of Police Squad -- presented with a bag of white powder, Norberg identifies it as a drug from a fingertip taste. Then, while the action continues in the foreground, he takes another fingertip, and another, and then a big fingerload, and starts rubbing it on his gums... When we next see him, he's high as a kite and draped around a piece of furniture.
 * A variation on the trope occurred on Barney Miller when Barney suspects some brownies baked by Wojo's girlfriend have hashish in them. He asks Harris to test the brownies, which Harris does... by eating one, rather than sending it to the lab as Barney had expected.
 * Has appeared a couple of times on Lost in the heroin-related subplots.
 * The Doctor does this with blood, even identifying the blood group, in the Doctor Who episode "The Christmas Invasion".
 * Ten developed a bit of a habit of um... licking things. Not necessarily always for diagnostic purposes.
 * Eleven does this as well. With a shed. To calculate how long it's been since it was built.
 * In the TV show Sisters, one of the sisters, Teddy, and her boyfriend come across some some drugs hidden in a shipment of clothes from her clothing line. The boyfriend open one of packages and tastes the drug. Teddy asks if it's heroin and he replies he doesn't know, that's just what they do on TV.
 * In an episode of The X Files, Mulder does this with digitalis. His tongue goes numb.
 * Mulder does this all the time, actually, including with some (fake) blood in "Revelations". Scully's face is a wonder to behold.
 * Fraser of Due South does this constantly, much to his partner's irritation.
 * Spoofed in one hilarious episode where the villain knows about Fraser's habit and sets a trap for him. Fraser finds a mysterious substance, sniffs and tastes it, looks confused, and keels over.
 * Spoofed in Just Shoot Me: Jack is about to take a bite of what he thinks is a diet pastry when Nina stops him, tastes the substance on top and declares it to be "Sugar, pure cane."
 * A version occurs in The Drew Carey Show, where Drew is suspected of being a drug addict. The cop assigned to the case goes through his house, finding various evidence that means he could be an addict, and having it explained away by the peculiarities of Drew being Drew. Then he finds the coffee table in the living room covered in white powder.

Drew: It's icing sugar. I have donuts sometimes when I'm watching TV.

Cop: Come on. You know how many donuts you'd have to eat to make this much--*tastes it* Ah, it's sugar."

"Ray: How do you know so much about it?
 * On another episode of The Drew Carey Show, a bag of what appears to be cocaine is found. An employee tastes it and says, "Interesting. I have no idea what cocaine tastes like."
 * Sam Tyler in Life On Mars not only identifies a sample of heroin but can tell from its colour that it's from Turkey... much to the suspicion of his police colleagues, as heroin is a new drug that's barely hit the street in 1973.

Gene: Because he's on it."

"Tim: Hang on a minute--(sniffs)--dang! That's certain substances, that is! How stupid...Graeme, have a sniff of that.
 * This is very anachronistic. Heroin was a major problem as of the turn of the century, much less the 1970s. Heroin just seems to make a comeback every few decades... the 1930s, 1950s, 1970s, and 2000s have all seen big comebacks for heroin.
 * In one episode of House, Thirteen does this when trying to track down what their patient's cocaine was cut with.
 * Justified, however, in that Thirteen has a chronic case of death wish.
 * Star Trek the Original Series: Kirk gives the taste test to a white powder he finds lying about on the "Arena" planet, but in that case it's potassium nitrate.
 * On Deep Space Nine Sisko once gave Gul'Dukat back a bottle of poisoned wine. Weyoun took a swig and declared it 'quite toxic'. He then explained that Vorta are immune to most poisons.
 * Averted on Law and Order SVU. When Elliot is undercover as a white-collar drug dealer, he "tests the product" of a potential supplier by feeling the powder's consistency. Asked why he doesn't taste it instead, he claims that they do random drug tests at his workplace; he only sells cocaine, he can't risk using it.
 * Beckett does the test and finds heroin in Castle. Castle comments on how badass she looked doing it.
 * Jasper Carrott and Robert Powell taste some white powder in crime-drama spoof The Detectives. Then they taste it again to make sure. Cut to the pair driving down the motorway at approximately 5mph, screaming "Slow down! Slow down!"
 * The Hyde persona in the British series Jekyll identified a soldier's age, diet, and number and breed of pets by smell and was also able to determine that he had cancer, where, and his life expectancy by tasting his sweat.
 * On The Incredible Hulk David taste-tested some white powder he found on his foot after transforming back from being the Hulk. (Hulk had rampaged through a warehouse full of drugs.) Possibly justified in that he is a doctor.
 * MacGyver tests a suspected drug sample this way, only to find out that it's keratin (powdered rhino horn).
 * Played for laughs on The Goodies, with smell instead of taste.

Graeme: Huh? Oh, that's--(sniffs -- collapses, then gets up, looking completely spaced out)--hooh! Where'd you get the stuff, man? Cool, baby, cool..."


 * Gill Grissom gets called out on this twice in CSI: early in the show, while trying to understand a woman's disappearance in a supermarket, he finds a yellow smudge on the floor and performs the fingertip dip taste test. Captain Brass, who was hovering nearby, winces in disgust and goes "Oh, that's sanitary." Luckily for Grissom, it was just mustard. But the second time he does it, much later in the series, it's Catherine who warns him that one of these days he'll really regret doing that.
 * "Reverend" Jim Ignatowski of Taxi was apparently able to tell that the coca leaves in some cookies baked by Latka came from "Peru... southern Peru, 1974... before the rains."
 * Chief Inspector Japp does this at least twice in Poirot - identifying cocaine in The Affair at the Victory Ball, and heroin in Evil Under the Sun.

Webcomics

 * Parodied on a VG Cats comic strip about Phoenix Wright Ace Attorney. His lovely female assistant finds residue from "some mysterious [white] liquid" all over his computer and tastes it. She exclaims, "Salty...must be blood!"
 * Parodied in this strip of Thinkin Lincoln (see page image).

Western Animation
"Bill No, this is soda Hank. (licks the outside of the tube) That's just grease."
 * Occurs in Family Guy, when Brian gets a job working as a police dog. He gains a cocaine addiction as a result.
 * A weird example from King of the Hill: When Hank suspects Dale topped off his mower's gas tank with water, Bill takes a drink from the fuel line.

"Principal Lewis: (does the fingertip taste test) Pure Peruvian marching powder. Grown on the Andes, north slope. I'd say it's about 80% baby laxative. Yeap, this junk means only one thing: Esteban Mortilla is back in business!"
 * Batman Beyond looks like he's going to do this; always dipping his finger into strange substances, but really he's using his suit's built in analyzer.
 * On American Dad Steve's high school principal is shockingly good at this.

Real Life

 * At least one Real Life police officer has been killed by doing this when the white powder turned out to be ricin, one of the top five deadliest poisons in the world.
 * Likewise, when methamphetamines were becoming popular, policy in many jurisdictions was for police officers to fan the air in suspected meth labs towards their noses in order to pick up on the fumes. Given the nature of meth fumes, most of the drug officers in at least one jurisdiction that did this eventually contracted throat and mouth cancer.
 * In chemistry, a brief fanning towards your nose is the recommended procedure if you need to smell something, versus shoving your schnoz directly into the beaker which can deck you. However, this should only be done if you have a reasonable expectation of the chemical, so you know what you're smelling is not (excessively) toxic. Smelling wholly unknown chemicals is like playing Russian Roulette.
 * It's said one of Sherlock Holmes' real life inspiration pulled a trick using this. The Professor had two vials of urine, one from a diabetic, he dips a finger in and taste it -- remarking that the diabetic is sweeter and forced all the students to repeat it. Then admonishes them for not paying attention. He had actually dipped in his pointer finger, but sucked on his middle finger.
 * Truth in Television, even without the admonishment. Prior to the development of chemical assays for glucose in urine, doctors really did detect it in this way. The "mellitus" in "diabetes mellitus" means "honey-flavored."
 * "It has to be chlorine". Indeed.
 * If the substance thus tested were fentanyl (or fentanyl-laced heroin), that could be trouble. Fentanyl is a synthetic opiate 100 times as potent as morphine (Heroin is roughly two-to-three times as effective as the same amount of morphine). There's a fentanyl analog used for tranquilizing elephants. One drop of it on your skin could kill you in seconds, unless artificial respiration were immediately administered.
 * Doctors and alchemists in older times often examined stuff by taste and smell - they didn't have much choice, as most of the more sophisticated methods didn't exist yet. This is probably one reason why people who dabbled in alchemy tended to get rather strange later in their lives. (Traditional alchemy is absolutely fascinated with mercury, and mercury fumes aren't good for the brain.)
 * At least one nineteenth century scientist insisted upon tasting every substance he discovered, though it was known, even then, to be very dangerous. He was found dead surrounded by dozens of substances, and with no way of knowing which did him in. Another discovered a compound which was absurdly sweet, incredibly tasty. He threw a party in which all the guests joined him in taking shots of he stuff. They were all dead by morning.
 * The first scientist has been urban-mythologized to be William Perkin Sr (creator of the first significant synthetic dye), who in fact died of pneumonia.
 * You can learn quite a bit about an unknown chemical by smelling it, though you should use the 'wafting' technique and fan the scents towards your nose. Esters usually smell sweet or fruity, sulfur compounds reek, and amines often smell fishy. Many working chemists also learn to identify common solvents by scent, and smell is often the first sense to warn you when something is boiling over, or has been left uncapped, or is reacting in unexpected ways.
 * Most artificial sweeteners were discovered when chemists noticed that their new chemical tasted incredibly sweet (or more often, failed to wash their hands after handling the chemical and found that everything they touched tasted sweet).
 * The psychedelic properties of LSD were first discovered through something similar to this -- though in LSD's case, it's slightly more justified than normal, since it wasn't ingested, but absorbed and took effect by touch. Following the initial discovery, the same scientist, Albert Hofmann, took a more controlled dose. The effects were somewhat stronger than he had expected.
 * Subverted almost every episode of COPS (well, every episode there's a drug test) with the baggie-test. Portable chemical tests the police have contain reactants that will change color in the presence of the primary component of the drug; if you've gone more than three episodes of that show without seeing the next contestant on Is It Blue at some point, count yourself lucky.