Dope: The providing of, use of, or an untenable substance or thing is a dope.
Source: http://www.worldwidewords.org/qa/qa-dop2.htm .
Historically, the word has had a wide variety of slangy associations. They include not only the lubricants and drugs you mention, but also information, a stupid person, and a varnish for cloth aircraft parts. Regionally in the US it has also meant Coca-Cola (because in its early years the drink was sold as a medicinal restorative and included some cocaine), the sprinkles on ice cream and various additives. In modern slang it can refer to something very good.
Dictionaries universally say that dope is from the old Dutch doop, a sauce or dip, from the verb doopen, to dip or mix.
Further the source mentions:
Somehow — we don’t know the details, but it was presumably at least in part the result of Irving’s fame as a writer — doup evolved into the slang dope. It appeared first in print as an ill-specified term for any thick liquid or glop. The earliest example that I’ve found — actually the derived verb — was in a newspaper article that listed deceptions practiced by sheep farmers:
Dope the sheep:— that is, put on oil and coloring to make a sheep look like the required breed; that is, paint the sheep as a common horse was once painted and sold for one of a superior race.
Sandusky Daily Commercial Register (Sandusky, Ohio), 17 Jun. 1856. You may feel that buyers of such sheep were more than a little unobservant.
In later years, dope was recorded for all sorts of stuff — among others a slop of mud and water to preserve the roots of trees awaiting planting, the chemical on the heads of matches, harness blacking, train axle grease, the material that nitroglycerine is absorbed in to make dynamite, sugar added to cans of sweetcorn and a lubricant for snowshoes:
There is hardly a man, woman, or child on this side of the continent who has not heard of “Snowshoe Thompson”, yet very few persons really know anything about him or his exploits. His were the first Norwegian snowshoes ever seen in the mountains, and at that time nothing was known of the mysterious “dope” — a preparation of pitch, which, being applied to the bottom of the shoes, enables the wearer to glide over snow softened by the rays of the sun. ... Without “dope” the soft snow stuck to, and so clogged his shoes that it was impossible for him to travel in it.
Albert Lea Enterprise (Albert Lea, Minnesota), 30 Mar. 1876. Norwegian snowshoes were actually skis, given that name to distinguish them from the racquet-shaped snowshoes used by native Americans. The word ski wasn’t then known.
It’s also recorded early on in the sense of a drug, either for humans or horses:
I learned something of his giving dope to his horses about the time he moved from Garrettsville to Chagrin Falls. ... I learned that he was giving his horse arsenic and laudanum.
Ashtabula Weekly Telegraph (Ashtabula, Ohio), 4 Dec. 1858. The owner thought giving arsenic to his horses would improve their health.
The “doc” made his own pills — “the real dope,” Camp said.
Waukesha Freeman (Waukesha, Wisconsin), 29 Mar. 1859.
More specifically in reference to drugs which are illegal today, though not necessarily illegal at the time (thus untenable):
This drug sense became widespread later in two specific ways, firstly in reference to the thick treacle-like preparation used in opium-smoking:
He persistently refuses to give the signs by which admittance may be had to the [opium] den, but he says that it is so jealously guarded that four doors have to be passed through before the smoking-room is reached, where a “dope” for ten cents, requiring about twenty minutes to smoke, is obtained, and on the bare floor of which the smokers lie extended during their torpor.
Northern Ohio Journal (Painesville, Ohio), 14 Jun. 1879.
This gave rise in the early 1880s to the term dope-fiend for an habitual user. Later, dope broadened to refer to all sorts of recreational narcotics, becoming widely known by the early twentieth century.
Not all "dope" was considered stupifying or particularly detrimental.
In the other branch of the drug sense, the term became specifically associated with drugging racehorses, either to improve their performance or degrade it:
The mare was two lengths ahead the first thirty yards, but suddenly let up, and was badly beaten. There is no doubt but that foul play was the cause of her losing, the mare having been “doped”.
Idaho Statesman (Boise, Idaho), 31 Jul. 1873.
Drugs of every name and description are used to “dope” horses so that they may win stakes. The poor animals are stuffed with all sorts of stimulants from sherry to strychnine. ... Such drugs as Fowler’s solution of arsenic, Spanish fly, cocaine, chloral, valerian, and belladonna, were employed.
Galveston Daily News (Galveston, Texas), 4 Jan. 1896.
This gave rise to "dope" being a restricted thing or secret knowledge, in the moral or legal sense:
Dope in the sense of information, particularly information that isn’t widely known or easily obtained, came directly from this practice. A whisper from the stables or some confederate telling a gambler which horses were being drugged was potentially worth a lot of money, so dope came to mean knowledge that drugs had been employed. This led to its being used for information about racing in general and later broadened still further.
A publication giving punters background information about horses at a track became humorously or sarcastically known as a dope book, also later a dope sheet; both were recorded in the 1890s and similarly these generalised later to refer to other topics. The phrases inside dope, real dope, true dope and straight dope — asserting the undisputed truth — were appearing in print by the early years of the new century:
Referee Bean gave out the following figures and the fight fans who want the straight dope will probably not miss it far by accepting them.
The Salt Lake Herald (Salt Lake City, Utah), 7 Apr. 1904.
Later various terms were used for illegal drugs to keep Narcs (Narcotics Police Officers) from knowing what the Beatniks or Hippies were talking about (grossly unfair, prejudicial and oversimplified characterisation of people who actually used drugs, but those are amongst the ones whom the Police would most often check; purposely leaving out yet another group who probably doesn't want to be associated with the corruption of young women).
These 'codes' were changed on rare occasions; the thought that the Police were not hip (in the know about 'secrets' of hippies) to what was going on is untrue.
Other illegal drugs had 'code words' too. Lysergic Acid Dyethylamide being shortened to LSD, Acid or 'cid. MDA becoming DA, etc. Cannabis became "weed" (because it grows wild and well), Hemp (because it's a relative, as is Hops. Later becoming dope, part from the scraping of resins from hands during cultivation, partially from scraping or solvent extraction and evaporation from pipes, the effect, and the cavalier and thoughtless use of the term as a code word for Marijuana (a word seldom used in North America).
The word "dope" is today not commonly used, except possibly by parents who do not smoke. The term Weed is far more common as is Cannabis if you're attempting to seem more educated or purport a medical use and gain support for your use of Cannabis (illegal in most places) upon the basis that it is a curative.
The use of the word "dope" pertaining to drugs is sufficiently old that the persons who could rightfully claimed to have popularized the term have long since passed.
Use in a sentence: That's the straight dope on dope, dope huh?