Subject of Avogadro's law Some are inert Some cause laughter Substances that can trap heat in the 27-Down, such as methane, 33-Across and 41-Across Some inert elements Some are noble Some are inert Some may be noble Some are inert '60s hallucinogen Some are noble Some are noble Some inert elements '60s hallucinogenic '60s trip starter, initially Some are noble Some are inert Some are inert Source of some strange visions '60s drug '60s hallucinogen '60s psychedelic Source of some strange visions, for short 1960s hits? Such as neon, hydrogen Such as neon, oxygen 1962 song, "__ Rebel" '60s turn-on Substance for Timothy Leary '60s drug briefly Some '60s hits? Something dropped before tripping? Some baby boomers dropped it '60s counterculture hallucinogenic '60s hallucinogen Source of some strange visions '60s psychedelic Sentry's welcome announcement Sentry's call Shakespeare contemporary George '60s hallucinogenic Shakespeare contemporary George 1960s counterculture drug '60s trip inducer Start of a trip? Start of some trips Some dropped tabs '60s trip inducer Something taken in preparation for a trip So-called 'battery acid' Stuff 'tested' in the 1960s' Acid Tests Subtext of Jefferson Airplane's 'White Rabbit' Subject of a repeated warning at Woodstock Subj. of 'The Electric Kool-Aid Acid Test' Subject of many '60s hits? Start of a trip, perhaps Start of a trip Source of some strange visions, for short 1960s mind alterer 1960s hits? '60s turn-on Substance for Timothy Leary '60s hallucinogen '60s hallucinogenic 1960s counterculture drug 1960s hallucinogen 1960s drug '60s drug '60s psychedelic '60s trip cause '60s tripping drug Source of some '60s trips '60s "acid" Sixties halucinogen Sixties drug, for short '60s drug Source of some flashbacks Sixties trip starter, initially '60s tripping drug Sixties hallucinogen Subj. in 'The Electric Kool-Aid Acid Test' Source of some '60s trips '60s 'acid' Something dropped at Woodstock Senators' supporters Sixties hallucinogen Substance associated with the C.I.A.'s controversial MK-ULTRA mind-control program '60s hallucinogen '60s hallucinogen Start of some trips Start of a trip, for short? Something dropped at Woodstock Stuff on blotter paper '60s hallucinogenic Source of some hallucinations Scandalous Strongly flavored, as meat Spirited Strong tasting. Strongly flavored. Slightly tainted Slightly tainted Strong-tasting, as meat Strong-tasting, as meat Smelly Speak, with "up" Shot amount Smoker's item Shot filler Shot unit Spoonful, perhaps Spreadsheet elements Slippers' companion Shot amount Spoonful, sometimes Sink part Spoonful of medicine, e.g. Subj. of Article 86 of the Uniform Code of Military Justice Spreadsheet makeup Spreadsheet units Spoonful, say Spreadsheet units Spoonful of medicine, say Spoonful of medicine, e.g St. Nick accessory Shot unit Spoonful, sometimes Sherlock Holmes item Snowman prop Shot in the arm, e.g Sherlock Holmes prop Snowman's prop Subject of a Magritte painting Small rooms Sudoku's little boxes Spreadsheet units Spreadsheet units Sherlock Holmes appurtenance Skateboarder's challenge Sherlock Holmes accessory Shot measurement Something that might spring a leak Sort of fitter St. Nick accessory Sherlock Holmes prop Snowman prop Stemmed item Snowman accessory Shot contents Smoke shop buy Spoonful, perhaps Subject of a Magritte painting (or not) Shot in the arm, say Shot of leaders from Diocese of Saint Etienne Skateboarder's challenge Sherlock Holmes appurtenance Sherlock Holmes accessory Shot of medicine Smuggler-chasing org. Something that might spring a leak Subject of a Magritte painting (or not) Snowman prop Stat on a medicine label Subject of a Magritte painting (or is it?) Syringe delivery Snowman accessory Sherlock Holmes prop Smuggler-stopping org. Smoke shop buy Snowman prop Snowman accessory Speak (up) Something under a sink Sherlock Holmes' smoke Speak (up) Smoke for Sherlock Syringe measurement Sherlock's calabash, for one Speak (up) Smoke for Sherlock Smuggler-stopping org Sheep trills? Smoker's item Sounds sheepish? Snowman prop Snowman's prop Snowman accessory Sheep noises Sheepish sounds Sheep trills Subject of a Magritte work (or not?) Snowman's smoke Sounds from the flock Sheepish comments Snowman's smoke Sheepish cries? Some albums sound better on it Something to trip on 1960s hallucinogen Something you might trip on Sounds at shearings '60s drug Sounds from the field Something dropped at Woodstock Sounds from the flock '60s "trip" inducer '60s hallucinogenic Sounds sheepish Sheepish comments '60s trip starter, initially '60s tripper's substance Sheep's cries Sheep sounds Source of a hippie's high, perhaps Source of some '60s trips Sheepish comments '60s "trip" drug Sheepish sounds '60s counterculture substance '60s hallucinogen '60s psychedelic drug Sounds from the meadow Substance of the '60s Sheep calls. Sheep to sheep. Sounds from a sheepcote. '60s hallucinogenic Sheep cries. Sounds at shearing time. Sounds sheepish. '60s hallucinogen Something dropped by one who trips? Sounds from the cote. '60s psychedelic Sounds from the fold. Sounds from a cote. Source of a Woodstock high Shot, e.g. '60s psychedelic '60s counterculture hallucinogenic '60s "trip" inducer '60s hallucinogenic Sheep sounds Sheep snorts Spoonful, maybe Shot in the arm, say '60s trip starter, initially '60s tripper's substance Source of a hippie's high, perhaps '60s "trip" drug