THE last time I was at the Viceroy of India in Wan Chai, ecstasy was curry slurry and fried potatoes piled up to your nose off a $90 buffet. Now, according to the papers, Ecstasy is a chemical compound in dinky tablet form allegedly circulating faster than a plate of hot poppadoms around dance parties at the restaurant on a Saturday night. Reports have it that soldiers of the Black Watch are implicated in the distribution of what the Scots might call ''wee sweeties'' and have been held, manacled in only their sporrans, in a dripping dungeon at the Stanley guard house. Implicated but, to their regret, not accommodated with them is, with the certainty of Lent Term following Michaelmas, an Island School schoolgirl. Charges are hovering heavier than helicopters. Sources close to the Elliot Ness Room at Wan Chai police station say the police are poised to shut down the parties at The Viceroy and return it as I remember it in the evenings to a close imitation of an abandoned ship's dining room. The problem is all to do with a stab at bliss, a rapture and exultation - emotions which somebody, somewhere in Hong Kong is probably working up a Private Member's Bill against this very minute. The tablet Ecstasy, which was allegedly the guest of honourat that Saturday party, packs in all of those and more, including a not inconsiderable dollop of self-esteem. So effective is it that the police could not help but record a disturbing concentration of happiness in the mezzanine levels of the Sung Hung Kai Centre. Probes could not detect any connection between the elation and the crashing of mahjong tiles, or theroar of castrated bullocks singing to backup tracks on TV screens or flushed gweilos with stomachs falling over their belts like dropped jellies belching ''My round!'' Worried by laughter not being made in ten part harmony by collective consensus, the police raided the joint. ''So many of the patrons appeared under the influence of drugs,'' reported Chief Inspector Lorimor in police-speak for people having ungazetted Fun. If the inspector is sensitive about large groups under the influence, I hope he rarely walks past my club of an evening or the line of sewers, open down Lockhart Road from noon to 4am. This attitude nutshells a problem which, unlike microchips, spare part surgery and video telephones, human society refuses to make progress on. Ecstasy was developed by the Germans in 1915 to help keep troops on their toes in the trenches. All right, so they lost but that was because they probably ended up making love not war. Half a tablet brings on a run of energy but, with it, a sense of touch which outstrips sex and having your back scratched combined. You feel good about yourself - and other people, to the extent that, if you are on speaking terms, you are crawling all over them. It appears we have had, for 80 years, a happiness tablet. What, by Aldous Huxley, is wrong with that? It is illegal, that's what. Yet, the only coherent objection to it held by the Hong Kong narcotics commissioner that I could identify on TV recently wasthat people in Ecstasy might forget to use a condom. A similar fastidiousness has not, in my experience, been a feature of those swaying at the bed head in a confluence of eight pints of Filipino or Danish formaldehyde. In the meantime ''Ecstatics'' have to buy the stuff at US$50 a go (HK$387), usually from an American Chinese called Jake on a phone number beginning with 119, and the rest of the world carries on drinking. I would have thought Lieut-Col Alistair McFahrquar-Campbell of that Ilk would be delighted that his Black Watch troops were into something so peaceable and convivial. Usually those boys do not consider they've had a good night out unless they have eight stitches to the scalp. At the end of a night in Wan Chai, the military police have to drop them with elephant gun sedatives. The lads would wander down the road to the fort, humming quietly arm in arm, their heads on each others shoulders . . . yes, well, perhaps not, colonel.